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<blockquote>''We’ve never faced this before, where clinical labs needed to very quickly be able to ramp up a test so fast.''<ref name="TerryCRISPR20">{{cite web |url=https://www.biospace.com/article/crispr-discoverer-jennifer-doudna-launches-covid-19-test-lab/ |title=CRISPR Pioneer Jennifer Doudna Expects Automated COVID-19 Test Lab to Begin Testing Next Week |work=BioSpace |author=Terry, M. |date=30 March 2020 |accessdate=10 April 2020}}</ref><br />&nbsp;<br />- Jennifer Doudna, Executive Director of the Innovative Genomics Institute, University of California, Berkeley</blockquote>
[[File:Test PCR dépistage SARS-CoV-2 prélèvement nasal Strasbourg 21 août 2020.jpg|right|thumb|400px|SARS-CoV-2 PCR screening test by nasal swab in Strasbourg on August 21, 2020.]]In the previous chapter, the most common testing methodologies for [[COVID-19]] and other [[Coronavirus|coronaviruses]] were discussed in detail. The prevailing method (often called the "gold standard") among them all is real-time reverse-transcription [[polymerase chain reaction]] (rRT-PCR) assays for testing. Broadly speaking, PCR is useful in pharmaceutical, biotechnology, and genetic engineering endeavors, as well as clinical diagnostics. As such, labs in those industries that already have PCR infrastructure in place have a theoretical step-up over labs that do not.


Though the dismantling and fund-cutting (proposed and real) of government programs designed to protect the populace from pandemics—as well as shortfalls in funding overall<ref name="SandsTheNeglect16">{{cite journal |title=The Neglected Dimension of Global Security — A Framework for Countering Infectious-Disease Crises |journal=The New England Journal of Medicine |author=Sands, P.; Mundaca-Shah, C.; Dzau, V.J. |volume=374 |issue=13 |pages=1281–87 |year=2016 |doi=10.1056/NEJMsr1600236 |pmid=26761419}}</ref>—have likely hobbled local, national, and global response to COVID-19<ref name="MorrisTrump20">{{cite web |url=https://fortune.com/2020/02/26/coronavirus-covid-19-cdc-budget-cuts-us-trump/ |title=Trump administration budget cuts could become a major problem as coronavirus spreads |work=Fortune |author=Morris, C. |date=26 February 2020 |accessdate=10 April 2020}}</ref><ref name="SpecterTheCorona20">{{cite web |url=https://www.newyorker.com/news/daily-comment/coronavirus-and-the-gutting-of-americas-public-health-system |title=The Coronavirus and the Gutting of America’s Public-Health System |work=The New Yorker |author=Specter, M. |date=17 March 2020 |accessdate=10 April 2020}}</ref><ref name="RoosCongress07">{{cite web |url=https://www.cidrap.umn.edu/news-perspective/2007/05/congress-cut-pandemic-funds-passing-spending-bill |title=Congress cut pandemic funds before passing spending bill |work=CIDRAP - News & Perspective |author=Roos, R. |date=25 May 2007 |accessdate=10 April 2020}}</ref><ref name="SchnirringCongress07">{{cite web |url=https://www.cidrap.umn.edu/news-perspective/2007/12/congress-slashes-pandemic-preparedness-funding |title=Congress slashes pandemic preparedness funding |work=CIDRAP - News & Perspective |author=Schnirring, L. |date=20 December 2007 |accessdate=10 April 2020}}</ref>, it should be recognized that this pandemic may arguably represent a once-in-a-century type of event.<ref name="GatesRespond20">{{cite journal |title=Responding to Covid-19 — A Once-in-a-Century Pandemic? |journal=The New England Journal of Medicine |author=Gates, B. |year=2020 |doi=10.1056/NEJMp2003762 |pmid=32109012}}</ref><ref name="ShontellMelinda20">{{cite web |url=https://www.businessinsider.com/melinda-gates-coronavirus-interview-vaccine-timeline-2020-4 |title=Melinda Gates: This is not a once-in-a-century pandemic. 'We will absolutely have more of these.' The billionaire philanthropist predicts a timeline for going back to normal |work=Business Insider |author=Shontell, A. |date=10 April 2020 |accessdate=10 April 2020}}</ref> That said, even the most well-prepared governments would still face challenges in quickly learning about, controlling, and developing therapies for a novel disease agent. Shortages in supplies, workers, funding, and other resources are inevitably caused with a pandemic as people across all types of infrastructure fall ill.<ref name="SandsTheNeglect16" /><ref name="MadhavPandemics17">{{cite book |url=https://www.ncbi.nlm.nih.gov/books/NBK525302/ |chapter=Chapter 17: Pandemics: Risks, Impacts, and Mitigation |title=Disease Control Priorities: Improving Health and Reducing Poverty |edition=3rd |author=Madhav, N.; Oppenheim, B.; Gallivan, M. et al. |editor=Jamison, D.T.; Gelband, H.; Horton, S. et al. |publisher=The World Bank |year=2017 |isbn=9781464805288}}</ref> This requires the additional human elements of adaptability, drive, and shared knowledge to find new and alternative solutions to fighting the challenges inherent to fighting against a novel disease.
PCR technology has advanced to the point where it is more efficient and user-friendly than prior, yet "the high cost of the instruments, servicing contracts, and reagents pose major challenges for the market, especially to the price-sensitive academics."<ref name="MWPoly20">{{cite web |url=https://www.marketwatch.com/press-release/polymerase-chain-reaction-market-sector-analysis-report-regional-outlook-competitive-share-forecast---2023-2020-06-23 |archiveurl=https://web.archive.org/web/20200809215548/https://www.marketwatch.com/press-release/polymerase-chain-reaction-market-sector-analysis-report-regional-outlook-competitive-share-forecast---2023-2020-06-23 |title=Polymerase Chain Reaction Market Sector Analysis Report, Regional Outlook & Competitive Share & Forecast - 2023 |author=Kenneth Research |work=MarketWatch |date=23 June 2020 |archivedate=09 August 2020 |accessdate=08 September 2021}}</ref> Writing about the thirty-fifth anniversary of PCR in 2018, science writer Alan Dove not only highlighted these cost issues but also the size and energy requirements for running the equipment. "As a result, one of the defining techniques of modern molecular biology has remained stubbornly inaccessible to educators and unusable in many remote locations."<ref name="DovePCR18">{{cite journal |title=PCR: Thirty-five years and counting |journal=Science |author=Dove, A. |volume=360 |issue=6389 |pages=670–672 |year=2018 |doi=10.1126/science.360.6389.673-c}}</ref> Various efforts have been made over the years to bring costs down by modifying how heating and temperature control are performed<ref name="WongARapid15">{{cite journal |title=A Rapid and Low-Cost PCR Thermal Cycler for Low Resource Settings |journal=PLoS One |author=Wong, G.; Wong, I. Chan, K. et al. |volume=10 |issue=7 |at=e0131701 |year=2015 |doi=10.1371/journal.pone.0131701}}</ref><ref name="KuznetsovDIYbio15">{{cite journal |title=DIYbio Things: Open Source Biology Tools as Platforms for Hybrid Knowledge Production and Scientific Participation |journal=Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems |author=Kuznetsov, S.; Doonan, C.; Wilson, N. et al. |pages=4065–68 |year=2015 |doi=10.1145/2702123.2702235}}</ref><ref name="NortonPhila16">{{cite web |url=https://www.bizjournals.com/philadelphia/news/2016/05/11/government-contract-biomeme-hiring-med-tech.html |title=Phila. med tech startup working on multimillion dollar government contract |author=Norton, D. |work=Philadelphia Business Journal |date=11 May 2016 |accessdate=06 August 2020}}</ref><ref name="AnLow20">{{cite journal |title=Low-Cost Battery-Powered and User-Friendly Real-Time Quantitative PCR System for the Detection of Multigene |journal=Micromachines |author=An, J.; Jiang, Y.; Shi, B. et al. |volume=11 |at=435 |year=2020 |doi=10.3390/mi11040435}}</ref>, but many of those system aren't typically optimal during a pandemic when turnaround time is critical.


See for example a non-peer-reviewed paper published on ''bioRxiv'' in early April 2020, where Schmid-Burgk ''et al.'' pointed out that though RT-PCR methods are the most common for currently testing for SARS-CoV-2, "global capacity for testing using these approaches, however, has been limited by a combination of access and supply issues for reagents and instruments." They proposed "a novel protocol that would allow for population-scale testing using massively parallel RT-LAMP by employing sample-specific barcodes." They claimed that a single heating step, pooled processing, and parallel sequencing with computational analysis would allow for the testing and tacking of "tens of millions of samples." Though the protocol was not validated with clinical samples, and concerns about sensitivity levels of RT-LAMP (an isothermal nucleic acid amplification technique that allows for RNA amplification) have been raised, the authors' work exemplifies the immediacy and ingenuity that has gone into finding workable solutions to a once-a-century problem.<ref name="Schmid-BurgkLAMP20">{{cite journal |title=LAMP-Seq: Population-Scale COVID-19 Diagnostics Using Combinatorial Barcoding |journal=bioRxiv |author=Schmid-Burgk, J.L.; Li, D.; Feldman, D. et al. |year=2020 |doi=10.1101/2020.04.06.025635}}</ref>
Amidst the pandemic, additional challenges also exist to those wanting to conduct PCR testing for COVID-19 and other viruses. As was discussed at the end of the previous chapter, supplies of reagents and consumables are not particularly robust mid-pandemic, with various shortages being reported off and on since the start of the pandemic.<ref name="HerperShortage20">{{cite web |url=https://www.statnews.com/2020/03/10/shortage-crucial-chemicals-us-coronavirus-testing/ |title=Shortage of crucial chemicals creates new obstacle to U.S. coronavirus testing |work=STAT |author=Herper, M.; Branswell, H. |date=10 March 2020 |accessdate=10 April 2020}}</ref><ref name="HaleQiagen20">{{cite web |url=https://www.fiercebiotech.com/medtech/qiagen-aims-to-more-than-quadruple-its-covid-19-reagent-production-6-weeks |title=Qiagen aims to more than quadruple its COVID-19 reagent production in 6 weeks |work=Fierce Biotech |author=Hale, C. |date=18 March 2020 |accessdate=10 April 2020}}</ref><ref name="MehtaMystery20">{{cite web |url=https://www.chemistryworld.com/news/mystery-surrounds-uk-claim-of-covid-19-test-reagent-shortage/4011457.article |title=Mystery surrounds UK claim of Covid-19 test reagent ‘shortage’ |work=Chemistry World |author=Mehta, A. |date=03 April 2020 |accessdate=07 September 2021}}</ref><ref name="RocheIrish20">{{cite web |url=https://www.irishtimes.com/news/science/irish-scientists-develop-reagent-in-effort-to-ease-covid-19-testing-delays-1.4223897 |title=Irish scientists develop reagent in effort to ease Covid-19 testing delays |work=The Irish Times |author=Roche, B. |date=08 April 2020 |accessdate=10 April 2020}}</ref><ref name="PadmaEfforts20">{{cite web |url=https://www.chemistryworld.com/news/efforts-to-combat-covid-19-in-india-hit-by-imported-reagent-shortages/4011718.article#/ |title=Efforts to combat Covid-19 in India hit by imported reagent shortages |author=Padma, T.V. |work=Chemistry World |date=13 May 2020 |accessdate=19 May 2020}}</ref><ref name="DavidSurvey20">{{cite web |url=https://abcnews.go.com/Health/survey-shows-resources-covid-19-diagnostic-testing-limited/story?id=71341885 |title=Survey shows resources for COVID-19 diagnostic testing still limited months later |author=David, E.; Farber, S.E. |work=ABC News |date=20 June 2020 |accessdate=08 July 2020}}</ref><ref name="JohnsonNCLabs20">{{cite web |url=https://patch.com/north-carolina/charlotte/nc-labs-facing-shortages-covid-19-testing-chemicals |title=NC Labs Facing Shortages In COVID-19 Testing Chemicals |author=Johnson, K. |work=Patch |date=02 July 2020 |accessdate=08 July 2020}}</ref><ref name="MervoshItsLike20">{{cite web |url=https://www.nytimes.com/2020/08/04/us/virus-testing-delays.html |title=‘It’s Like Having No Testing’: Coronavirus Test Results Are Still Delayed |author=Mervosh, S.; Fernandez, M. |work=The New York Times |date=04 August 2020 |accessdate=05 August 2020}}</ref><ref name="CourageCovid20">{{cite web |url=https://www.vox.com/2020/7/31/21336212/covid-19-test-results-delays |title=Should we be testing fewer people to stop the spread of Covid-19? |author=Courage, K.H. |work=Vox |date=31 July 2020 |accessdate=05 August 2020}}</ref><ref name="ASMSupply20">{{cite web |url=https://asm.org/Articles/2020/September/Clinical-Microbiology-Supply-Shortage-Collecti-1 |title=Supply Shortages Impacting COVID-19 and Non-COVID Testing |author=American Society for Microbiology |publisher=American Society for Microbiology |date=09 November 2020 |accessdate=18 November 2020}}</ref><ref name="AbbottCovid20">{{cite web |url=https://www.wsj.com/articles/covid-19-testing-saps-supplies-needed-for-other-medical-tests-11604926800 |title=Covid-19 Testing Saps Supplies Needed for Other Medical Tests |author=Abbott, B.; Krouse, S. |work=The Wall Street Journal |date=09 November 2020 |accessdate=18 November 2020}}</ref><ref name="WilliamsSupply21">{{cite web |url=https://www.the-scientist.com/news-opinion/supply-shortages-hit-life-science-labs-hard-68695 |title=Supply Shortages Hit Life Science Labs Hard |author=Williams, S. |work=The Scientist |date=21 April 2021 |accessdate=07 September 2021}}</ref> Some of these shortages have gradually worked themselves out over time, but they highlight the need for other varying methods that don't necessarily depend on the same reagents and consumables that are in short supply.


Another example of ingenuity in the face of difficult circumstances can be found at the University of California, Berkeley. At the beginning of the pandemic, its Innovative Genomics Institute (IGI) rapidly repurposed a 2,500-square-foot scientific lab into an automated diagnostic laboratory that could initially process more than 1,000 patient samples per day, with the ability to ramp up to 3,000 per day thanks to robotics and a streamlined workflow. Partnering with dozens of people from Thermo Fisher Scientific, Salesforce, Third Wave Analytics, and Hamilton Corp., the lab focused on not only turnaround time but also accuracy of results through automation. Their continued success, of course, still relies on a steady supply of reagents and related supplies from Thermo Fisher.<ref name="TerryCRISPR20" /><ref name="SandersUCBerk20">{{cite web |url=https://news.berkeley.edu/2020/03/30/uc-berkeley-scientists-spin-up-a-robotic-covid-19-testing-lab/ |title=UC Berkeley scientists spin up a robotic COVID-19 testing lab |work=Berkeley News |author=Sanders, R. |date=30 March 2020 |accessdate=10 April 2020}}</ref>
For those labs wishing to adopt PCR testing of viruses—particularly COVID-19—into their workflow while providing reasonable turnaround times, all is not lost. However, careful planning is required. For example, you'll want to keep in mind that some PCR machines require vendor-specific reagents. If you're going to acquire a particular instrument, you'll want to do due diligence by verifying not only the supported reagents but also those reagents' overall availability (real and projected). You'll also want to consider factors such as anticipated workload (tests per day), what your workflow will look like, and how to balance overall investment with the need for reasonable turnaround times.  


Since the pandemic's start, others have also expressed concerns about the global supply of reagents necessary to test for SARS-CoV-2. Successful testing using RT-PCR requires two different enzymes: reverse transcriptase, for converting RNA to DNA, and polymerase, for amplifying the converted DNA. These enzymes and other reagent components may be instrument-specific, and at least one component has to be sympathetic to detection of the target virus' RNA. Little of this can be prepared without a proper sequence of the virus in question. Dr. Ronald Leonard, president and medical director of Cytocheck Laboratory and medical director of the Labette Health hospital, expressed the difficulties associated with reagent manufacturing thusly<ref name="NoltingLocal20">{{cite web |url=https://www.parsonssun.com/news/coronavirus/article_99193646-7aec-11ea-a7c5-b700f82332db.html |title=Local testing delayed by lack of reagents |work=Parsons Sun |author=Nolting, R. |date=10 April 2020 |accessdate=10 April 2020}}</ref>:
An increasing body of research is being produced suggesting ways to improve turnaround times with PCR testing for COVID-19, with many research efforts focusing on cutting out RNA extraction steps entirely. Alcoba-Florez ''et al.'' [[Journal:Fast SARS-CoV-2 detection by RT-qPCR in preheated nasopharyngeal swab samples|propose]] direct heating of the sample-containing nasopharyngeal swab at 70 °C for 10 minutes in place of RNA extraction.<ref name="Alcoba-FlorezFast20">{{cite journal |title=Fast SARS-CoV-2 detection by RT-qPCR in preheated nasopharyngeal swab samples |journal=International Journal of Infectious Diseases |author=Alcoba-Florez, J.; González-Montelongo, R.; Íñigo-Campos, A.; García-Martínezde Artola, D.; Gil-Campesino, H.;<br />The Microbiology Technical Support Team; Ciuffreda, L.; Valenzuela-Fernández, A.; Flores, C. |volume=97 |pages=66–68 |year=2020 |doi=10.1016/j.ijid.2020.05.099}}</ref> Adams ''et al.'' have proposed an "adaptive PCR" method using a non-standard reagent mix that skips RNA extraction and can act "as a contingency for resource‐limited settings around the globe."<ref name="ShapiroStream20">{{cite web |url=https://news.vanderbilt.edu/2020/07/29/streamlined-diagnostic-approach-to-covid-19-can-avoid-potential-testing-logjam/ |title=Streamlined diagnostic approach to COVID-19 can avoid potential testing logjam |author=Shapiro, M. |work=Research News @ Vanderbilt |date=29 July 2020 |accessdate=06 August 2020}}</ref><ref name="AdamsCOVID20">{{cite journal |title=COVID‐19 diagnostics for resource‐limited settings: Evaluation of “unextracted” qRT‐PCR |journal=Journal of Medical Virology |author=Adams, N.M.; Leelawong, M.; Benton, A. et al. |year=2020 |doi=10.1002/jmv.26328}}</ref> Wee ''et al.'' skip RNA extraction and nucleic acid purification by using a single-tube homogeneous reaction method run on a lightweight, portable thermocycler.<ref name="MeharImproving20">{{cite web |url=https://www.techexplorist.com/improving-speed-gold-standard-covid-19-diagnostic-test/34069/ |title=Improving the speed of gold-standard COVID-19 diagnostic test |author=Mehar, P. |work=Tech Explorist |date=27 July 2020 |accessdate=06 August 2020}}</ref><ref name="WeeRapid20">{{cite journal |title=Rapid Direct Nucleic Acid Amplification Test without RNA Extraction for SARS-CoV-2 Using a Portable PCR Thermocycler |journal=Genes |author=Wee, S.K.; Sivalingam, S.P.; Yap, E.P.H. |volume=11 |issue=6 |at=664 |year=2020 |doi=10.3390/genes11060664}}</ref> Other innovations include tweaking reagents and enzymes to work with one step, skipping the reverse transcription step,<ref name="CSIRFaster20">{{cite web |url=https://www.engineeringnews.co.za/article/faster-local-covid-19-test-kits-could-be-ready-by-year-end-2020-07-30/ |title=Faster, local COVID-19 test kits could be ready by year-end |author=Council for Scientific and Industrial Research |work=Engineering News |publisher=Creamer Media |date=30 July 2020 |accessdate=07 August 2020}}</ref> and using saliva-based molecular testing that skips RNA extraction.<ref name="RanoaSaliva20">{{cite journal |title=Saliva-Based Molecular Testing for SARS-CoV-2 that Bypasses RNA Extraction |journal=bioRxiv |author=Ranoa, D.R.E.; Holland, R.L.; Alnaji, F.G. et al. |year=2020 |doi=10.1101/2020.06.18.159434}}</ref><ref name="ThomasFast20">{{cite web |url=https://www.news-medical.net/news/20200806/Fast-cheap-and-easy-COVID-19-test-from-Yale.aspx |title=Fast, cheap and easy COVID-19 test from Yale |author=Thomas, L. |work=News Medical - Life Sciences |date=06 August 2020 |accessdate=16 August 2020}}</ref>


<blockquote>With the instant demand for SARS-CoV-2 testing, the manufacturing process had to start from scratch for the SARS-CoV-2 specific components, and this did cause a lag time before reagents were available. The increased demand coupled with the decision to only allocate reagents to two national laboratories, some state health departments, and to "hot spots" has compounded the difficulty for laboratories like ours to obtain the necessary reagents to perform the testing.</blockquote>
'''Saliva as a specimen'''


Reports of COVID-19 test reagent shortages from various sources have appeared since March 2020.<ref name="HerperShortage20">{{cite web |url=https://www.statnews.com/2020/03/10/shortage-crucial-chemicals-us-coronavirus-testing/ |title=Shortage of crucial chemicals creates new obstacle to U.S. coronavirus testing |work=STAT |author=Herper, M.; Branswell, H. |date=10 March 2020 |accessdate=10 April 2020}}</ref><ref name="HaleQiagen20">{{cite web |url=https://www.fiercebiotech.com/medtech/qiagen-aims-to-more-than-quadruple-its-covid-19-reagent-production-6-weeks |title=Qiagen aims to more than quadruple its COVID-19 reagent production in 6 weeks |work=Fierce Biotech |author=Hale, C. |date=18 March 2020 |accessdate=10 April 2020}}</ref><ref name="MehtaMystery20">{{cite web |url=https://www.chemistryworld.com/news/mystery-surrounds-uk-claim-of-covid-19-test-reagent-shortage/4011457.article |title=Mystery surrounds UK claim of Covid-19 test reagent ‘shortage’ |work=Chemistry World |author=Mehta, A. |date=03 April 2020 |accessdate=07 September 2021}}</ref><ref name="RocheIrish20">{{cite web |url=https://www.irishtimes.com/news/science/irish-scientists-develop-reagent-in-effort-to-ease-covid-19-testing-delays-1.4223897 |title=Irish scientists develop reagent in effort to ease Covid-19 testing delays |work=The Irish Times |author=Roche, B. |date=08 April 2020 |accessdate=10 April 2020}}</ref><ref name="PadmaEfforts20">{{cite web |url=https://www.chemistryworld.com/news/efforts-to-combat-covid-19-in-india-hit-by-imported-reagent-shortages/4011718.article#/ |title=Efforts to combat Covid-19 in India hit by imported reagent shortages |author=Padma, T.V. |work=Chemistry World |date=13 May 2020 |accessdate=19 May 2020}}</ref><ref name="DavidSurvey20">{{cite web |url=https://abcnews.go.com/Health/survey-shows-resources-covid-19-diagnostic-testing-limited/story?id=71341885 |title=Survey shows resources for COVID-19 diagnostic testing still limited months later |author=David, E.; Farber, S.E. |work=ABC News |date=20 June 2020 |accessdate=08 July 2020}}</ref><ref name="JohnsonNCLabs20">{{cite web |url=https://patch.com/north-carolina/charlotte/nc-labs-facing-shortages-covid-19-testing-chemicals |title=NC Labs Facing Shortages In COVID-19 Testing Chemicals |author=Johnson, K. |work=Patch |date=02 July 2020 |accessdate=08 July 2020}}</ref><ref name="MervoshItsLike20">{{cite web |url=https://www.nytimes.com/2020/08/04/us/virus-testing-delays.html |title=‘It’s Like Having No Testing’: Coronavirus Test Results Are Still Delayed |author=Mervosh, S.; Fernandez, M. |work=The New York Times |date=04 August 2020 |accessdate=05 August 2020}}</ref><ref name="CourageCovid20">{{cite web |url=https://www.vox.com/2020/7/31/21336212/covid-19-test-results-delays |title=Should we be testing fewer people to stop the spread of Covid-19? |author=Courage, K.H. |work=Vox |date=31 July 2020 |accessdate=05 August 2020}}</ref><ref name="ASMSupply20">{{cite web |url=https://asm.org/Articles/2020/September/Clinical-Microbiology-Supply-Shortage-Collecti-1 |title=Supply Shortages Impacting COVID-19 and Non-COVID Testing |author=American Society for Microbiology |publisher=American Society for Microbiology |date=09 November 2020 |accessdate=18 November 2020}}</ref><ref name="AbbottCovid20">{{cite web |url=https://www.wsj.com/articles/covid-19-testing-saps-supplies-needed-for-other-medical-tests-11604926800 |title=Covid-19 Testing Saps Supplies Needed for Other Medical Tests |author=Abbott, B.; Krouse, S. |work=The Wall Street Journal |date=09 November 2020 |accessdate=18 November 2020}}</ref><ref name="WilliamsSupply21">{{cite web |url=https://www.the-scientist.com/news-opinion/supply-shortages-hit-life-science-labs-hard-68695 |title=Supply Shortages Hit Life Science Labs Hard |author=Williams, S. |work=The Scientist |date=21 April 2021 |accessdate=07 September 2021}}</ref> Over time, those shortages even extended to supplies for non-COVID-19 tests such as those for strep throat, bronchitis, mycobacterial infections, urinary-tract infections, fungal infections, and sexually transmitted infections.<ref name="ASMSupply20" /><ref name="AbbottCovid20" /><ref name="WilliamsSupply21" /> In the face of these supply challenges, some have taken matters into their own hands. Noting Irish laboratories' difficulties sourcing lysis buffer (for isolating molecules of interest and keeping them stable), Cork Institute of Technology's Dr. Brigid Lucey worked with several other virologists and microbiologists early in the pandemic, as well as with pharmaceutical company Eli Lilly, to produce a custom-formulated yet high-quality lysis buffer for not only Irish laboratories but also other countries can take advantage of. "We are happy to share what we found with other countries and it’s important our scientists retain their skills to make this kind of formulation because we may need to do this again in the future if we get other pandemics," she said.<ref name="RocheIrish20" />
The saliva molecular tests in particular are intriguing. Talk of the potential utility of using saliva as a specimen for COVID-19 was occurring as early as April 2020<ref name="XuSaliva20">{{cite journal |title=Saliva: Potential diagnostic value and transmission of 2019-nCoV |journal=International Journal of Oral Science |author=Xu, R.; Cui, B.; Duan, X. et al. |volume=12 |at=11 |year=2020 |doi=10.1038/s41368-020-0080-z}}</ref><ref name="GreenwoodSaliva20">{{cite web |url=https://news.yale.edu/2020/04/24/saliva-samples-preferable-deep-nasal-swabs-testing-covid-19 |title=Saliva samples preferable to deep nasal swabs for testing COVID-19 |author=Greenwood, M. |work=YaleNews |date=24 April 2020 |accessdate=01 May 2020}}</ref>, and the first saliva-based COVID-19 test, produced by Spectrum Solutions in cooperation with RUCDR Infinite Biologics Laboratory<ref name="SSFirst20">{{cite web |url=https://spectrumsolution.com/fda-authorized-covid-19-updates/ |title=First saliva collection device FDA EUA authorized for COVID-19 testing |publisher=Spectrum Solutions |date=2020 |accessdate=16 August 2020}}</ref> and Vault Health<ref name="VHVault20">{{cite web |url=https://www.prnewswire.com/news-releases/vault-health-launches-first-of-its-kind-saliva-based-fda-eua-approved-test-for-covid-19-301039633.html |title=Vault Health Launches First-of-its-Kind Saliva-based FDA EUA Approved Test for COVID-19 |author=Vault Health |work=PR Newswire |date=14 April 2020 |accessdate=01 May 2020}}</ref>, was given an FDA EUA in April 2020. On August 15, 2020, Yale School of Public Health was given an EUA for it SalivaDirect molecular test. Although still PCR-based (and a CLIA high-complexity test), SalivaDirect is being touted as a means to improve specimen collection safety, consume fewer reagents, prove compatible with high-throughput workflow, and cut overall turnaround time. Not only is saliva easier to collect and safer for healthcare staff, the test is essentially "open sourced," not requiring proprietary equipment from Yale, making the test more flexible by being validated to reliably function with a wider array of reagents and instruments.<ref name="GallagherFDA20">{{cite web |url=https://www.contagionlive.com/view/fda-grants-emergency-covid19-authorization-yale-open-source-method-saliva-testing |title=FDA Grants Emergency COVID-19 Authorization to Yale's Open Source Method of Saliva Testing |author=Gallagher, G.M. |work=ContagionLive |date=15 August 2020 |accessdate=16 August 2020}}</ref><ref name="ZillgittFDA20">{{cite web |url=https://www.usatoday.com/story/sports/nba/2020/08/15/fda-approves-covid-19-saliva-test-developed-yale-nba-nbpa-aid/5590452002/ |title=FDA approves COVID-19 saliva test developed at Yale in partnership with the NBA, NBPA |author=Zillgitt, J. |work=USA Today |date=15 August 2020 |accessdate=16 August 2020}}</ref> When compared to using a nasopharyngeal swab specimen using the ThermoFisher Scientific TaqPath COVID-19 combo kit, results were comparable 94.1% of the time.<ref name="ThomasFast20" /> While sensitivity and specificity may be slightly less comparable to other PCR options<ref name="WeisslederCOVID20">{{cite web |url=https://csb.mgh.harvard.edu/covid |title=COVID-19 Diagnostics in Context |author=Weissleder, R.; Lee, H.; Ko, J. et al. |publisher=Harvard Center for Systems Biology |date=15 August 2020 |accessdate=16 August 2020}}</ref>, the overall advantages during reagent shortages and a definitive need for broader testing likely outweigh the slightly lesser sensitivity and specificity. In November 2020, public health agencies in Arizona and Minnesota reportedly began running trials of free saliva-based molecular testing.<ref name="ParsonsPlaces20">{{cite web |url=https://www.azfamily.com/news/continuing_coverage/coronavirus_coverage/places-with-saliva-based-covid-testing-expecting-influx-of-people/article_76ac95c4-26b5-11eb-b34e-3728b1308927.html |title=Places with saliva-based COVID testing expecting influx of people |author=Parsons, J. |work=AZFamily |date=14 November 2020 |accessdate=19 November 2020}}</ref><ref name="MDoHState20">{{cite web |url=https://www.health.state.mn.us/news/pressrel/2020/covid102220.html |title=State launches pilot of COVID-19 test at home saliva program |author=Minnesota Department of Health |publisher=Minnesota Department of Health |date=22 October 2020}}</ref>  


Another challenge lies in the accuracy of serology-based antibody tests, let alone how much they actually tell us about immunity. FierceBiotech's Conor Hale touched upon this in late April 2020<ref name="HaleCongress20">{{cite web |url=https://www.fiercebiotech.com/medtech/congress-urges-fda-to-better-police-evaluate-covid-19-antibody-tests |title=Congress urges FDA to better police, evaluate COVID-19 antibody tests |author=Hale, C. |work=Fierce Biotech |date=27 April 2020 |accessdate=01 May 2020}}</ref>:
As the pandemic has progressed into 2021, saliva testing has become even more attractive, in particular for at-home over-the-counter testing.<ref name="PugleNininv21">{{cite web |url=https://www.healthline.com/health-news/noninvasive-saliva-tests-for-covid-19-as-effective-as-nose-throat-swabs |title=Noninvasive Saliva Tests for COVID-19 as Effective as Nose, Throat Swabs |author=Pugle, M. |work=Healthline |date=20 January 2021 |accessdate=08 September 2021}}</ref><ref name="KarkusDiff21">{{cite web |url=https://www.pharmacytimes.com/view/differences-between-saliva-covid-19-tests-nasal-swab-covid-19-tests |title=Differences Between Saliva COVID-19 Tests, Nasal Swab COVID-19 Tests |author=Karkus, T. |work=Pharmacy Times |date=05 April 2021 |accessdate=08 September 2021}}</ref> In August 2021, Spectrum Solutions received an EUA for its Spectrum Solutions SDNA-1000 saliva collection system, specifically designed "to avoid user collection errors" and eliminate "the requirement for any bio-sample temperature-controlled storage or transport,"<ref name="NSMedStaffSpect21">{{cite web |url=https://www.nsmedicaldevices.com/news/spectrum-solutions-covid-19-testing/ |title=Spectrum Solutions’ device gets FDA EUA for unsupervised saliva collection for Covid-19 testing |author=NS Medical Staff Writer |work=NS Medical Devices |date=18 August 2021 |accessdate=08 September 2021}}</ref> arguably upping the game for new saliva-based test kits going forward. Additionally, as variants of COVID-19 continue to crop up, additional saliva-based at-home tests are coming into development. For example, researchers at the Wyss Institute, the Massachusetts Institute of Technology, and Boston-area hospitals have been working on a laboratory-developed test called Minimally Instrumented SHERLOCK (miSHERLOCK) based on CRISPR (clustered regularly interspaced short palindromic repeats) technology. The researchers claim that the test, able to be used with typical off-the-shelf components, "works as well as the gold standard PCR tests and could cost as little as $3 per test."<ref name="HealthDayAtHome21">{{cite web |url=https://www.webmd.com/lung/news/20210807/at-home-saliva-test-can-spot-covid-variants#1 |title=At-Home Saliva Test Can Spot COVID Variants |author=HealthDay News |work=WebMD |date=06 August 2021 |accessdate=08 September 2021}}</ref><ref name="DePuigMinim21">{{cite journal |title=Minimally instrumented SHERLOCK (miSHERLOCK) for CRISPR-based point-of-care diagnosis of SARS-CoV-2 and emerging variants |journal=Science Advances |author=De Puig, H.; Lee, R.A.; Najjar, D. et al. |volume=7 |issue=32 |at=eabh2944 |year=2021 |doi=10.1126/sciadv.abh2944 |pmid=34362739 |pmc=PMC8346217}}</ref>
 
<blockquote>Compared to molecular tests—which sequence and match the RNA of the novel coronavirus to produce a result—the FDA has described antibody tests that gauge the body’s immune system response as a less-complicated endeavor that could proceed without review, dubbed “regulatory flexibility” by Commissioner Stephen Hahn. This policy shift has led to confusion, with some antibody test developers falsely claiming their tests are FDA-approved or could diagnose COVID-19 at home. Still others have sold outrightly fraudulent tests online.</blockquote>
 
At least in the U.S., these problems are compounded by company participation in test validation of EUAs being voluntary.<ref name="HaleCongress20" /> As a late April 2020 memorandum from Congress put it: "FDA is unable to validate the accuracy of antibody tests that are already on the market, and companies are ignoring requests from the Department of Health and Human Services (HHS) to voluntarily submit their tests for validation ... FDA has failed to police the coronavirus serological antibody test market, has taken no public enforcement action against any company, and has not conveyed any clear policy on serological tests..."<ref name="SORPremim20">{{cite web |url=https://oversight.house.gov/sites/democrats.oversight.house.gov/files/ECP%20Staff%20Report%20on%20Preliminary%20Findings%20of%20the%20Subcommittee%E2%80%99s%20Coronavirus%20Antibody%20Testing%20Investigation.pdf |format=PDF |title=Preliminary Findings of the Subcommittee’s Coronavirus Antibody Testing Investigation |author=Subcommittee on Economic and Consumer Policy |publisher=U.S. House of Representatives |date=24 April 2020 |accessdate=01 May 2020}}</ref> The entire memorandum is revealing in the challenges of attempting to relax social distancing measures under the pretense of the effectiveness of antibody testing. Entities such as the University of California - San Francisco<ref name="FarleyTesting20">{{cite web |url=https://www.ucsf.edu/news/2020/04/417276/testing-tests-covid-19-antibody-assays-scrutinized-accuracy-ucsf-uc-berkeley |title=Testing the Tests: COVID-19 Antibody Assays Scrutinized for Accuracy by UCSF, UC Berkeley Researchers |author=Farley, P.; Sanders, R. |work=UCSF News |date=27 April 2020 |accessdate=01 May 2020}}</ref> and the University of California - Berkeley<ref name="SandersWhat20">{{cite web |url=https://news.berkeley.edu/2020/04/27/what-covid-19-antibody-tests-can-tell-us-and-what-they-cant/ |title=What COVID-19 antibody tests can tell us, and what they can’t |author=Sanders, R. |work=Berkeley News |date=27 April 2020 |accessdate=01 May 2020}}</ref> early on emphasized the importance of elements such as sensitivity, specificity, proper training, and the unknowns of the predictive ability of the test. Even assays running under trusted platforms such as PCR can reveal issues. For example, Thermo Fisher Scientific's TaqPath COVID019 Combo Kit, approved for EUA in March 2020, received scrutiny and updates to address issues with false-positive and -negative results<ref name="WhooleyFDA20">{{cite web |url=https://www.massdevice.com/fda-warns-on-false-results-for-thermo-fisher-taqpath-covid-19-testing-kit/ |title=FDA warns on false results for Thermo Fisher TaqPath COVID-19 testing kit |author=Whooley, S. |work=+ Mass Device |publisher=WTWH Media LLC |date=17 August 2020 |accessdate=23 August 2020}}</ref><ref name="TaylorThermo20">{{cite web |url=https://www.medtechdive.com/news/thermo-fisher-covid-19-test-flagged-for-false-positive-false-negative-resu/583682/ |title=Thermo Fisher COVID-19 test flagged for false positive and negative results |author=Taylor, N.P. |work=MedTechDive |date=18 August 2020 |accessdate=23 August 2020}}</ref>, highlighting the difficulty of, at least early on in the pandemic, balancing the need for rapidly approving test kits for emergency use while also maintaining some semblance of oversight regarding their effectiveness and proper use. This has been further hampered by an August 2020 decision that stated the FDA could not require laboratory developed tests (LDTs) to be submitted for an EUA. As the Pew Charitable Trust's Liz Richardson argued in September 2021, reversing this decision "would enable labs to continue bringing innovative and effective new tests to market quickly while empowering FDA to protect the public from faulty products that allow infection to spread."<ref name="RichardsonWith21">{{cite web |url=https://www.pewtrusts.org/en/research-and-analysis/articles/2021/09/02/with-delta-surging-fda-needs-authority-to-ensure-accuracy-of-covid19-tests |title=With Delta Surging, FDA Needs Authority to Ensure Accuracy of COVID-19 Tests |author=Richardson, L. |publisher=Pew Charitable Trust |date=02 September 2021 |accessdate=07 September 2021}}</ref>
 
Finally, while point-of-care testing, including at-home testing, has made strides in 2021<ref name="FDAInVitroAntigen21">{{cite web |url=https://www.fda.gov/medical-devices/coronavirus-disease-2019-covid-19-emergency-use-authorizations-medical-devices/in-vitro-diagnostics-euas-antigen-diagnostic-tests-sars-cov-2 |title=In Vitro Diagnostics EUAs - Antigen Diagnostic Tests for SARS-CoV-2 |publisher=U.S. Food and Drug Administration |date=07 September 2021 |accessdate=07 September 2021}}</ref>, their need remains apparent. Dozens of at-home tests remained in development (many of them antigen tests) at the end of 2020, and even now a major barrier is found in making them both accurate and easy for untrained people to understand and use.<ref name="WanHome20">{{cite web |url=https://www.washingtonpost.com/health/2020/10/24/coronavirus-home-tests/ |title=Home tests could help in the fight against the coronavirus. So where are they? |author=Wan, W. |work=The Washington Post |date=24 October 2020 |accessdate=18 November 2020}}</ref><ref name="McDermottInner20">{{cite journal |title=Inner Workings: Researchers race to develop in-home testing for COVID-19, a potential game changer |journal=PNAS |author=McDermott, A. |volume=117 |issue=42 |pages=25956-25959 |year=2020 |doi=10.1073/pnas.2019062117 |pmid=32999063 |pmc=PMC7584891}}</ref> And as more at-home tests continue to receive EUAs in 2021, they are still not without concern, particularly in regards to ensuring that at-home test results get reported properly and rapidly.<ref name="WanHome20" /><ref name="Crear-PerryTheHidden20">{{cite web |url=https://www.statnews.com/2020/11/05/rapid-covid-19-tests-hidden-public-health-hazard/ |title=The hidden public health hazard of rapid Covid-19 tests |author=Crear-Perry, J. |work=STAT |date=05 November 2020 |accessdate=18 November 2020}}</ref> One such early example at the end of 2020 was Lucira Health's LAMP-based Lucira COVID-19 All-In-One Test Kit, which was approved as a prescription-based at-home test, but with the stipulation that the prescribing healthcare provider would be responsible for reporting results.<ref name="RomoFDAApproves20">{{cite web |url=https://www.npr.org/sections/coronavirus-live-updates/2020/11/17/936055284/fda-approves-first-at-home-coronavirus-test |title=FDA Approves 1st At-Home Coronavirus Test |author=Romo, V. |work=NPR |date=17 November 2020 |accessdate=18 November 2020}}</ref> Such a requirement arguably can and should be put in place for at-home antigen-based testing as well.<ref name="WanHome20" />
 
As the pandemic churns through its second year, it's more important than ever for leaders across government, healthcare, and the media to continue to not spread misinformation and not make decisions based on poor scientific evidence. It will take organized efforts from multiple stakeholders—such as that found with a June 2020 NIH workshop on expanding and improving COVID-19 antibody tests<ref name="NIHExperts20">{{cite web |url=https://www.nih.gov/news-events/news-releases/experts-identify-steps-expand-improve-antibody-tests-covid-19-response |title=Experts identify steps to expand and improve antibody tests in COVID-19 response |author=National Institutes of Health |work=News Releases |date=23 June 2020 |accessdate=08 July 2020}}</ref>—to continue to find responsible solutions to the challenges we still face with this pandemic.


==References==
==References==
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{{Reflist|colwidth=30em}}
==Citation information for this chapter==
'''Chapter''': 2. Diagnostic testing of COVID-19 and other coronaviruses
'''Edition''': Fall 2021
'''Title''': ''COVID-19 Testing, Reporting, and Information Management in the Laboratory''
'''Author for citation''': Shawn E. Douglas
'''License for content''': [https://creativecommons.org/licenses/by-sa/4.0/ Creative Commons Attribution-ShareAlike 4.0 International]
'''Publication date''': September 2021

Revision as of 19:16, 3 February 2022

SARS-CoV-2 PCR screening test by nasal swab in Strasbourg on August 21, 2020.

In the previous chapter, the most common testing methodologies for COVID-19 and other coronaviruses were discussed in detail. The prevailing method (often called the "gold standard") among them all is real-time reverse-transcription polymerase chain reaction (rRT-PCR) assays for testing. Broadly speaking, PCR is useful in pharmaceutical, biotechnology, and genetic engineering endeavors, as well as clinical diagnostics. As such, labs in those industries that already have PCR infrastructure in place have a theoretical step-up over labs that do not.

PCR technology has advanced to the point where it is more efficient and user-friendly than prior, yet "the high cost of the instruments, servicing contracts, and reagents pose major challenges for the market, especially to the price-sensitive academics."[1] Writing about the thirty-fifth anniversary of PCR in 2018, science writer Alan Dove not only highlighted these cost issues but also the size and energy requirements for running the equipment. "As a result, one of the defining techniques of modern molecular biology has remained stubbornly inaccessible to educators and unusable in many remote locations."[2] Various efforts have been made over the years to bring costs down by modifying how heating and temperature control are performed[3][4][5][6], but many of those system aren't typically optimal during a pandemic when turnaround time is critical.

Amidst the pandemic, additional challenges also exist to those wanting to conduct PCR testing for COVID-19 and other viruses. As was discussed at the end of the previous chapter, supplies of reagents and consumables are not particularly robust mid-pandemic, with various shortages being reported off and on since the start of the pandemic.[7][8][9][10][11][12][13][14][15][16][17][18] Some of these shortages have gradually worked themselves out over time, but they highlight the need for other varying methods that don't necessarily depend on the same reagents and consumables that are in short supply.

For those labs wishing to adopt PCR testing of viruses—particularly COVID-19—into their workflow while providing reasonable turnaround times, all is not lost. However, careful planning is required. For example, you'll want to keep in mind that some PCR machines require vendor-specific reagents. If you're going to acquire a particular instrument, you'll want to do due diligence by verifying not only the supported reagents but also those reagents' overall availability (real and projected). You'll also want to consider factors such as anticipated workload (tests per day), what your workflow will look like, and how to balance overall investment with the need for reasonable turnaround times.

An increasing body of research is being produced suggesting ways to improve turnaround times with PCR testing for COVID-19, with many research efforts focusing on cutting out RNA extraction steps entirely. Alcoba-Florez et al. propose direct heating of the sample-containing nasopharyngeal swab at 70 °C for 10 minutes in place of RNA extraction.[19] Adams et al. have proposed an "adaptive PCR" method using a non-standard reagent mix that skips RNA extraction and can act "as a contingency for resource‐limited settings around the globe."[20][21] Wee et al. skip RNA extraction and nucleic acid purification by using a single-tube homogeneous reaction method run on a lightweight, portable thermocycler.[22][23] Other innovations include tweaking reagents and enzymes to work with one step, skipping the reverse transcription step,[24] and using saliva-based molecular testing that skips RNA extraction.[25][26]

Saliva as a specimen

The saliva molecular tests in particular are intriguing. Talk of the potential utility of using saliva as a specimen for COVID-19 was occurring as early as April 2020[27][28], and the first saliva-based COVID-19 test, produced by Spectrum Solutions in cooperation with RUCDR Infinite Biologics Laboratory[29] and Vault Health[30], was given an FDA EUA in April 2020. On August 15, 2020, Yale School of Public Health was given an EUA for it SalivaDirect molecular test. Although still PCR-based (and a CLIA high-complexity test), SalivaDirect is being touted as a means to improve specimen collection safety, consume fewer reagents, prove compatible with high-throughput workflow, and cut overall turnaround time. Not only is saliva easier to collect and safer for healthcare staff, the test is essentially "open sourced," not requiring proprietary equipment from Yale, making the test more flexible by being validated to reliably function with a wider array of reagents and instruments.[31][32] When compared to using a nasopharyngeal swab specimen using the ThermoFisher Scientific TaqPath COVID-19 combo kit, results were comparable 94.1% of the time.[26] While sensitivity and specificity may be slightly less comparable to other PCR options[33], the overall advantages during reagent shortages and a definitive need for broader testing likely outweigh the slightly lesser sensitivity and specificity. In November 2020, public health agencies in Arizona and Minnesota reportedly began running trials of free saliva-based molecular testing.[34][35]

As the pandemic has progressed into 2021, saliva testing has become even more attractive, in particular for at-home over-the-counter testing.[36][37] In August 2021, Spectrum Solutions received an EUA for its Spectrum Solutions SDNA-1000 saliva collection system, specifically designed "to avoid user collection errors" and eliminate "the requirement for any bio-sample temperature-controlled storage or transport,"[38] arguably upping the game for new saliva-based test kits going forward. Additionally, as variants of COVID-19 continue to crop up, additional saliva-based at-home tests are coming into development. For example, researchers at the Wyss Institute, the Massachusetts Institute of Technology, and Boston-area hospitals have been working on a laboratory-developed test called Minimally Instrumented SHERLOCK (miSHERLOCK) based on CRISPR (clustered regularly interspaced short palindromic repeats) technology. The researchers claim that the test, able to be used with typical off-the-shelf components, "works as well as the gold standard PCR tests and could cost as little as $3 per test."[39][40]

References

  1. ↑ Kenneth Research (23 June 2020). "Polymerase Chain Reaction Market Sector Analysis Report, Regional Outlook & Competitive Share & Forecast - 2023". MarketWatch. Archived from the original on 09 August 2020. https://web.archive.org/web/20200809215548/https://www.marketwatch.com/press-release/polymerase-chain-reaction-market-sector-analysis-report-regional-outlook-competitive-share-forecast---2023-2020-06-23. Retrieved 08 September 2021. 
  2. ↑ Dove, A. (2018). "PCR: Thirty-five years and counting". Science 360 (6389): 670–672. doi:10.1126/science.360.6389.673-c. 
  3. ↑ Wong, G.; Wong, I. Chan, K. et al. (2015). "A Rapid and Low-Cost PCR Thermal Cycler for Low Resource Settings". PLoS One 10 (7): e0131701. doi:10.1371/journal.pone.0131701. 
  4. ↑ Kuznetsov, S.; Doonan, C.; Wilson, N. et al. (2015). "DIYbio Things: Open Source Biology Tools as Platforms for Hybrid Knowledge Production and Scientific Participation". Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems: 4065–68. doi:10.1145/2702123.2702235. 
  5. ↑ Norton, D. (11 May 2016). "Phila. med tech startup working on multimillion dollar government contract". Philadelphia Business Journal. https://www.bizjournals.com/philadelphia/news/2016/05/11/government-contract-biomeme-hiring-med-tech.html. Retrieved 06 August 2020. 
  6. ↑ An, J.; Jiang, Y.; Shi, B. et al. (2020). "Low-Cost Battery-Powered and User-Friendly Real-Time Quantitative PCR System for the Detection of Multigene". Micromachines 11: 435. doi:10.3390/mi11040435. 
  7. ↑ Herper, M.; Branswell, H. (10 March 2020). "Shortage of crucial chemicals creates new obstacle to U.S. coronavirus testing". STAT. https://www.statnews.com/2020/03/10/shortage-crucial-chemicals-us-coronavirus-testing/. Retrieved 10 April 2020. 
  8. ↑ Hale, C. (18 March 2020). "Qiagen aims to more than quadruple its COVID-19 reagent production in 6 weeks". Fierce Biotech. https://www.fiercebiotech.com/medtech/qiagen-aims-to-more-than-quadruple-its-covid-19-reagent-production-6-weeks. Retrieved 10 April 2020. 
  9. ↑ Mehta, A. (3 April 2020). "Mystery surrounds UK claim of Covid-19 test reagent ‘shortage’". Chemistry World. https://www.chemistryworld.com/news/mystery-surrounds-uk-claim-of-covid-19-test-reagent-shortage/4011457.article. Retrieved 07 September 2021. 
  10. ↑ Roche, B. (8 April 2020). "Irish scientists develop reagent in effort to ease Covid-19 testing delays". The Irish Times. https://www.irishtimes.com/news/science/irish-scientists-develop-reagent-in-effort-to-ease-covid-19-testing-delays-1.4223897. Retrieved 10 April 2020. 
  11. ↑ Padma, T.V. (13 May 2020). "Efforts to combat Covid-19 in India hit by imported reagent shortages". Chemistry World. https://www.chemistryworld.com/news/efforts-to-combat-covid-19-in-india-hit-by-imported-reagent-shortages/4011718.article#/. Retrieved 19 May 2020. 
  12. ↑ David, E.; Farber, S.E. (20 June 2020). "Survey shows resources for COVID-19 diagnostic testing still limited months later". ABC News. https://abcnews.go.com/Health/survey-shows-resources-covid-19-diagnostic-testing-limited/story?id=71341885. Retrieved 08 July 2020. 
  13. ↑ Johnson, K. (2 July 2020). "NC Labs Facing Shortages In COVID-19 Testing Chemicals". Patch. https://patch.com/north-carolina/charlotte/nc-labs-facing-shortages-covid-19-testing-chemicals. Retrieved 08 July 2020. 
  14. ↑ Mervosh, S.; Fernandez, M. (4 August 2020). "‘It’s Like Having No Testing’: Coronavirus Test Results Are Still Delayed". The New York Times. https://www.nytimes.com/2020/08/04/us/virus-testing-delays.html. Retrieved 05 August 2020. 
  15. ↑ Courage, K.H. (31 July 2020). "Should we be testing fewer people to stop the spread of Covid-19?". Vox. https://www.vox.com/2020/7/31/21336212/covid-19-test-results-delays. Retrieved 05 August 2020. 
  16. ↑ American Society for Microbiology (9 November 2020). "Supply Shortages Impacting COVID-19 and Non-COVID Testing". American Society for Microbiology. https://asm.org/Articles/2020/September/Clinical-Microbiology-Supply-Shortage-Collecti-1. Retrieved 18 November 2020. 
  17. ↑ Abbott, B.; Krouse, S. (9 November 2020). "Covid-19 Testing Saps Supplies Needed for Other Medical Tests". The Wall Street Journal. https://www.wsj.com/articles/covid-19-testing-saps-supplies-needed-for-other-medical-tests-11604926800. Retrieved 18 November 2020. 
  18. ↑ Williams, S. (21 April 2021). "Supply Shortages Hit Life Science Labs Hard". The Scientist. https://www.the-scientist.com/news-opinion/supply-shortages-hit-life-science-labs-hard-68695. Retrieved 07 September 2021. 
  19. ↑ Alcoba-Florez, J.; González-Montelongo, R.; Íñigo-Campos, A.; García-Martínezde Artola, D.; Gil-Campesino, H.;
    The Microbiology Technical Support Team; Ciuffreda, L.; Valenzuela-Fernández, A.; Flores, C. (2020). "Fast SARS-CoV-2 detection by RT-qPCR in preheated nasopharyngeal swab samples". International Journal of Infectious Diseases 97: 66–68. doi:10.1016/j.ijid.2020.05.099.     
  20. ↑ Shapiro, M. (29 July 2020). "Streamlined diagnostic approach to COVID-19 can avoid potential testing logjam". Research News @ Vanderbilt. https://news.vanderbilt.edu/2020/07/29/streamlined-diagnostic-approach-to-covid-19-can-avoid-potential-testing-logjam/. Retrieved 06 August 2020. 
  21. ↑ Adams, N.M.; Leelawong, M.; Benton, A. et al. (2020). "COVID‐19 diagnostics for resource‐limited settings: Evaluation of “unextracted” qRT‐PCR". Journal of Medical Virology. doi:10.1002/jmv.26328. 
  22. ↑ Mehar, P. (27 July 2020). "Improving the speed of gold-standard COVID-19 diagnostic test". Tech Explorist. https://www.techexplorist.com/improving-speed-gold-standard-covid-19-diagnostic-test/34069/. Retrieved 06 August 2020. 
  23. ↑ Wee, S.K.; Sivalingam, S.P.; Yap, E.P.H. (2020). "Rapid Direct Nucleic Acid Amplification Test without RNA Extraction for SARS-CoV-2 Using a Portable PCR Thermocycler". Genes 11 (6): 664. doi:10.3390/genes11060664. 
  24. ↑ Council for Scientific and Industrial Research (30 July 2020). "Faster, local COVID-19 test kits could be ready by year-end". Engineering News. Creamer Media. https://www.engineeringnews.co.za/article/faster-local-covid-19-test-kits-could-be-ready-by-year-end-2020-07-30/. Retrieved 07 August 2020. 
  25. ↑ Ranoa, D.R.E.; Holland, R.L.; Alnaji, F.G. et al. (2020). "Saliva-Based Molecular Testing for SARS-CoV-2 that Bypasses RNA Extraction". bioRxiv. doi:10.1101/2020.06.18.159434. 
  26. ↑ 26.0 26.1 Thomas, L. (6 August 2020). "Fast, cheap and easy COVID-19 test from Yale". News Medical - Life Sciences. https://www.news-medical.net/news/20200806/Fast-cheap-and-easy-COVID-19-test-from-Yale.aspx. Retrieved 16 August 2020. 
  27. ↑ Xu, R.; Cui, B.; Duan, X. et al. (2020). "Saliva: Potential diagnostic value and transmission of 2019-nCoV". International Journal of Oral Science 12: 11. doi:10.1038/s41368-020-0080-z. 
  28. ↑ Greenwood, M. (24 April 2020). "Saliva samples preferable to deep nasal swabs for testing COVID-19". YaleNews. https://news.yale.edu/2020/04/24/saliva-samples-preferable-deep-nasal-swabs-testing-covid-19. Retrieved 01 May 2020. 
  29. ↑ "First saliva collection device FDA EUA authorized for COVID-19 testing". Spectrum Solutions. 2020. https://spectrumsolution.com/fda-authorized-covid-19-updates/. Retrieved 16 August 2020. 
  30. ↑ Vault Health (14 April 2020). "Vault Health Launches First-of-its-Kind Saliva-based FDA EUA Approved Test for COVID-19". PR Newswire. https://www.prnewswire.com/news-releases/vault-health-launches-first-of-its-kind-saliva-based-fda-eua-approved-test-for-covid-19-301039633.html. Retrieved 01 May 2020. 
  31. ↑ Gallagher, G.M. (15 August 2020). "FDA Grants Emergency COVID-19 Authorization to Yale's Open Source Method of Saliva Testing". ContagionLive. https://www.contagionlive.com/view/fda-grants-emergency-covid19-authorization-yale-open-source-method-saliva-testing. Retrieved 16 August 2020. 
  32. ↑ Zillgitt, J. (15 August 2020). "FDA approves COVID-19 saliva test developed at Yale in partnership with the NBA, NBPA". USA Today. https://www.usatoday.com/story/sports/nba/2020/08/15/fda-approves-covid-19-saliva-test-developed-yale-nba-nbpa-aid/5590452002/. Retrieved 16 August 2020. 
  33. ↑ Weissleder, R.; Lee, H.; Ko, J. et al. (15 August 2020). "COVID-19 Diagnostics in Context". Harvard Center for Systems Biology. https://csb.mgh.harvard.edu/covid. Retrieved 16 August 2020. 
  34. ↑ Parsons, J. (14 November 2020). "Places with saliva-based COVID testing expecting influx of people". AZFamily. https://www.azfamily.com/news/continuing_coverage/coronavirus_coverage/places-with-saliva-based-covid-testing-expecting-influx-of-people/article_76ac95c4-26b5-11eb-b34e-3728b1308927.html. Retrieved 19 November 2020. 
  35. ↑ Minnesota Department of Health (22 October 2020). "State launches pilot of COVID-19 test at home saliva program". Minnesota Department of Health. https://www.health.state.mn.us/news/pressrel/2020/covid102220.html. 
  36. ↑ Pugle, M. (20 January 2021). "Noninvasive Saliva Tests for COVID-19 as Effective as Nose, Throat Swabs". Healthline. https://www.healthline.com/health-news/noninvasive-saliva-tests-for-covid-19-as-effective-as-nose-throat-swabs. Retrieved 08 September 2021. 
  37. ↑ Karkus, T. (5 April 2021). "Differences Between Saliva COVID-19 Tests, Nasal Swab COVID-19 Tests". Pharmacy Times. https://www.pharmacytimes.com/view/differences-between-saliva-covid-19-tests-nasal-swab-covid-19-tests. Retrieved 08 September 2021. 
  38. ↑ NS Medical Staff Writer (18 August 2021). "Spectrum Solutions’ device gets FDA EUA for unsupervised saliva collection for Covid-19 testing". NS Medical Devices. https://www.nsmedicaldevices.com/news/spectrum-solutions-covid-19-testing/. Retrieved 08 September 2021. 
  39. ↑ HealthDay News (6 August 2021). "At-Home Saliva Test Can Spot COVID Variants". WebMD. https://www.webmd.com/lung/news/20210807/at-home-saliva-test-can-spot-covid-variants#1. Retrieved 08 September 2021. 
  40. ↑ De Puig, H.; Lee, R.A.; Najjar, D. et al. (2021). "Minimally instrumented SHERLOCK (miSHERLOCK) for CRISPR-based point-of-care diagnosis of SARS-CoV-2 and emerging variants". Science Advances 7 (32): eabh2944. doi:10.1126/sciadv.abh2944. PMC PMC8346217. PMID 34362739. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8346217. 
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