Charite, a Germany’s most influential virologist in respect of COVID-19 employee of Christian Drosten said that they did not use purified particles for testing virus.
MagNA pure 96 system (Roche,Penzberg,Germany) was use to extract RNA from clinical sample. Viral RNA mini kit (QIAGEN, Hilden,Germany) was used to extract RNA from cell culture supernatants.
False positive tests are because of the irrationality in testing like fully recovered patients in China’s Guangdong province with COVID-19 has tested positive again. Wang chen, president of Chinese Academy of Medical Sciences told that PCR tests are only 30-50 % accurate. Sin Hang Lee from Milford Molecular Diagnostics Laboratory has sent a letter to WHO on 22nd March 2020 that RTqPCR (Reverse Transcriptase quantitative PCR) test kits used to detect SARS-COV-2 RNA in humans is giving many false positive results and failing to detect some real positive cases.
Even CDC and FDA has given in their files that SARS-COV-2 RTPCR test not suitable for diagnosing SARS-COV-2. CDC 2019 – nCOV RT-PCR diagnostics panel on March 30,2020 said that detection of viral RNA in the samples cannot say that nCOV -2019 is the causative agent for clinical symptoms and the test cannot differentiate between other bacterial or viral pathogens.
PCR or other tests cannot even detect the targeted genes of SARS-COV-2. RT-qPCR is a qualitative tests rather than quantitative as prescribed on description of kit. So these tests will not say how many viral particles are there in the body which is crucial as the patient need to have million and millions of viral particles actively replicating in their body to be ill.
Drosten PCR test uses unspecific E-gene assay as preliminary assay a and Institute Pasteur uses E-gene as confirmatory assay. E-gene is likely to detect all Asian viruses and not specific for sequences of SARS-COV-2.
So, at the beginning of April WHO changed the norms and recommended that a test can be regarded as positive even if just the E-gene assay gives a positive result which means a confirmed unspecific test result is officially sold as specific. E-gene assay produce by Roche, TIB Molbiol and R-Biopharm.
