Why is Yale's new crown saliva test called a "breakthrough" by the FDA director?

Over the weekend, the FDA announced that it had granted the SalivaDirect New Coronary Diagnostic Test Emergency Use Authorization (EUA), developed by yale University School of Public Health, a breakthrough in improving testing efficiency and avoiding reagent shortages, FDA Administrator Dr. Stephen M. Hahn said in a FDA press release.
concept of using saliva samples to detect new coronavirus is not new, and the FDA has previously issued EUA for four molecular diagnostic tests based on saliva samples. The nucleic acid removal step we already know that large-scale nucleic acid testing and tracking of people who have come into contact with infected patients is one of the effective means of controlling the expansion of the new crown outbreak.
most common detection method is to use nasopharyngeal swabs to obtain samples for RT-PCR-based nucleic acid detection.
, however, the process of obtaining a nasopharyngeal swab sample is not a very comfortable process for people, and most of the current nucleic acid testing requires steps to purify the nucleic acid from the sample.
this step not only increases the time and cost of processing samples, but may also affect the speed of new crown detection due to a shortage of nucleic acid purification kits.
at Yale University's School of Public Health are trying to develop a "simple version" of the new coronavirus test based on saliva samples.
first, they found that the new coronavirus RNA in saliva was as stable at room temperature and at 30 degrees C as it was at 4 degrees C without adding preservatives.
means that saliva samples do not need special sample bottles to collect, and any sterile sample bottle can be used to collect saliva samples, facilitating the collection of saliva samples.
, the researchers further explore ways to simplify the nucleic acid detection process.
After simplifying the sample processing process to add protease K, a protease commonly used in DNA extraction, to the degradation protein in the sample, the treated sample was used directly for the RT-PCR testing process, removing the steps to purify the nucleic acid from the sample.
researchers found that the results from the "simple version" testing process of removing purified nucleic acid extraction steps based on saliva samples were 94% more relevant than conventional RT-PCR tests using purified nucleic acid steps based on nasopharyngeal swabs.
SalivaDirect nucleic acid testing processes and test performance (Photo source: Resources) extended the scope of testing to allow this test to be used in more testing laboratories, and the researchers also tested protease K and RT-PCR kits produced by different manufacturers.
they found that a variety of common protease K and RT-PCR kits could be used in this "simple version" of the new crown detection process, detecting sensitivity of 6-12 copies/microliers of new coronavirus.
means that many testing labs don't need to buy special reagents, which can be built using reagents already at hand by following the testing process released by Yale University.
researchers at Yale University who have validated reagents and instruments for the SalivaDirect process (Photo: Reference 3) also say they will provide an "open source" testing process for all interested laboratories to help them improve the efficiency of new coronavirus detection.
at the same time, they are further validating the ability of this testing process to identify asymptomatic patients.
researchers say the study is an important step in that direction, as new coronavirus detection requires constant innovation to make them faster, more convenient and more accessible while maintaining accuracy.
: s1. Coronavirus (COVID-19) Update: FDA Issues Emergency Use Authorization to Yale School of Public Health for SalivaDirect, Which a New Method of Saliva Process Sampleing. Retrieved August 16, 2020, from Quick and Afford saliva-based COVID-19 test developed by Yale scientists receives FDA Emergency Use Authorization. Retrieved August 16, 2020, from Vogels et al., (2020). SalivaDirect: Simple and sensitive molecular diagnostic test for SARS-CoV-2 surveillance. medRxiv, original title: Yale University's "simple version" of the new crown saliva test was authorized for emergency use, why is it called a "breakthrough" by the FDA director? Follow Medicinal Mingkangde on WeChat Public No.