Excellent work, Mike, as usual. Any chance I might be able to republish this wonderful piece at www.Snooze2Awaken.com ... ?

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Very interesting. Reminds me of other images meant to show replication of viruses and viral activity https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8139691/ this on diarrhoea virus.

I think this is where the nonsense of trypsin dependence comes from, doing uncontrolled experiments. The addition of trypsin (or proteinase K) is also essential to show the desired cytopathic effects (CPE) which proves the ‘virus’ is there. However adding trypsin to uninfected cultures also causes CPE. Immunofluoresence assay (IFA) is another way to show ‘viral activity’. IFA detects the antigens thought to be from the virus eg the glycoprotein of the ‘spike’. The proteins (antigens) are labelled with a fluorescent marker linked to an antibody, thereby making the protein visible.

Predigestion with trypsin is a common lab technique used to break protein links and ‘unmask’ hidden antigens in patient samples. Once they are unmasked the antigens can be labelled with antibodies, such as those used in IFA, so that the antigens can be visualised. In virology world an increase in IFA by addition of trypsin means that the presence of trypsin in a host organism is essential to split the spike protein at the ‘cleavage’ site and facilitate entry of the virus into the cell, where it then replicates, making more copies of the antigen (and more florescence). The lack of activity by not adding trypsin shows that the spike subunit is trypsin dependent (4). To anyone with any sense it would indicate that adding a digestive enzyme to cultures increases CPE’s and IFA by disrupting proteins and unmasking and visualising previously undetected antigens. Not adding any trypsin leaves these proteins masked and undetected.



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