[Kylie Drake]

Hi all,

All of the initial validation work we did with the BOMB protocol utilised positive patient samples that had been heat inactivated at 56C for 30 minutes.

While there was a slight decrease in the Ct values we achieved with these samples compared to that which was obtained prior to extraction, it was considered negligible. Heat inactivation is not our normal process with patient samples.

I note with interest in my recent readings that this paper in JCM (https://jcm.asm.org/content/early/2020/04/03/JCM.00512-20) references a Chin J Lab Med paper that must make reference to the fact that heat inactivation may degrade coronavirus RNA and lead to false negative results in samples with low viral titers. Indeed this appears to have been the case with SARS too.

Somebody specifically asked about heat inactivation and the BOMB protocol on Twitter, so I thought I would highlight this paper (although I have not read the original). This likely won’t be a problem in countries that are attempting to flatten the curve, but will be an issue in countries that are beginning to move to surveillance only and see asymptomatic patients with low viral titers.

Cheers,

Kylie

[Phil Oberacker]

Hi Kylie,

Thanks! That is actually important to know!

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