JCM: Sample inactivation will lead to COVID19 testing false negatives

June 4, 2020 /PRNewswire/--- In order to protect medical laboratory personnel from infection when testing clinical samples of SARS-CoV-2, most laboratories inactivate virus samples before testingThe effect of inactivation on the test results has not yet been determined, but it is estimated that the false negative rate caused by inactivation is 30 to 50 per cent(photo source:researchers at the Centers for Disease Control and Prevention in Xi'an speculated that the virus inactivation may have been the cause of false negativesThey have now tested several inactivation methods to determine whether they reduce the sensitivity of virus detection in clinical samplesThe study was published in The American Society for Microbiologyresearchers took clinical samples from 63 patients infected with SARS-CoV-2They first used digital PCR technology to determine the total number of virus particles in each samplethen, they inactivate the virus from the sample and find that the number of viruses detected by the same means has decreased significantlyThe first inactivated treatment uses a reagent called TRIzol, which destroys 47.54 percent of the nuclear shell gene and nearly 40 percent of ORF 1abThe second inactivation process heated the sample to 56 degrees C for 30 minutes and reduced the detection of the two genes by 48.55% and 56.40%, respectivelyHeat to 80 degrees C for 20 minutes, further reducing the number of copies of the virus, boiling or after 121 degrees C autoclave, almost no detectable viruses are foundresearchers believe that TRIzol should be used as the best means of inactivation of samplesBecause trIzol has the least impact on RNA copy numbers in the method sated(Bio Valley Bioon.com)Source: Small Study sample sample in maylead to SARS-CoV-2 negative Snr
Original Origin: Hailong Chen et al, Influence of Inactive Methods on Of Inactive Methods on Severe Severe Draper Draper Coronavirus 2 RNA Copy, Journal Journal of Clinical Micro Biology (2020) DOI: 10.1128/JCM.00958-20