Todays news — well done

[J HancockParticipant @jhancock95746]

Just out of interest, does anyone know if wiping handles, etc, down with a petrol soaked rag will kill 'it ' ?

[Martin KyteParticipant @martinkyte99762]

Posted by pgk pgk on 06/04/2020 12:26:25:

Feezing stuff for storage is quite an involved procedure. I have no knowledge of current methods but certainly back in the day freezing sperm involved mixing it with egg proteins and being careful about the speed and final temperatures reached and importantly the stability of that final temperature.

A quick google on freezing viruses for storage (which may/may not apply to this specific virus) gave these two quotes:

<<Virus Freezing

However, RNA and most enveloped viruses are extremely heat labile and need to be snap-frozen (frozen rapidly) and stored at -80°C for long-term storage. Please note that most viruses will suffer damage if storage temperatures exceed greater than -60°C. 1.>>

and

<<Viruses frozen in water are likely to be inactivated by the water's relatively low pH. … He adds that viruses are more likely to survive in a frozen state if they freeze and thaw only once, as the freeze-thaw process kills at least 90% of virus each time.>>

Obviously time in the freezer has a big effect as would condensation on the packet before the freeze 'took' So the risk is probably lower than first thoughts would suggest. It;s also worth remembering SOD's comments re postman handling packages… the difference between someone sneezing slime on the enevelope and the relative smaller amount of particles likely to be deposited by the item being put in the letterbox.

Supermarket risk is going to be greatest from all the asymptomatic folk breathing your way and accumulated virus particles from multiple handling of objects – notable the trolley handles (if supermarket isn't cleaning them) check-out belts and card machines.

pgk

You are quite corrrect. Indeed our proceedures for freezing samples for Cryo-Electronmicroscopy involves plunging grids into liquid ethane. This not only preserves the folded state of the protein but creates non crystaline ice which doesn't interfere with imaging.

Slow freezing will certainly be much less efficient in preserving virus largely through the crystal formation. However what is in question is not the preservation but the destruction of virus particles and slow freezing cannot really be seen as a way of destroying virus. Some may certainly survive.

I agree with you your trip to the supermarket is the major risk.

regards Martin

[John Paton 1Participant @johnpaton1]

JH, in the absence of authoritative reply to your question, I would suggest 'probably not' – stick to soap which we have been told time and again by the experts is the best method. (it is also cheap and kind to the skin!)

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