Decontaminating workbench with HCl and EtOH? - (Feb/28/2010 )

I work in a molecular lab dealing with viral rna/dna
I was told to wipe worktops first with 0.1% HCl followed by 70% EtOH.
in my previous job, I have always been wiping with just EtOH (though it wasnt a molecular lab)

I would like to know why the two types of wipes?

Thanks!

Square Pig on Mar 1 2010, 03:09 AM said:

Hello,
first of all, accurate working and working conditions are the best way to avoid any contamination of RNA/ DNA.

Strong recommendation: Forget that HCl story!

Take care of your health - exposure to these fumes is not the best for your lungs. Besides, your bench will not like it either.
This is definately not a typical method in a molecular lab.

What about the classic way? EtOH, Isoprop, RNase-Away,...

Square Pig on Feb 28 2010, 09:09 PM said:

All we use are EtoH and RNAse Away. Sometimes Bacdown.

The HCl damages nucleic acid residues by acid hydrolysis. At 0.1% it is very unlikely to be fuming, so this should not be a worry. Having said that, unless your work practices are poor you shouldn't have too much problem with contamination.

It may be that the practice was instituted to remove viruses from the bench, though you would be better off using trigene or virkon for this purpose.

10 % sodium hypochlorite ( Hypex ) was fine in our lab ...

We use diluted bleach (made fresh every 2 weeks).

Thanks for the replies!

I was told that EtOH is effective against nucleic acids and HCl against non-enveloped virus.
Could anyone kindly explain to me the reactions which take place.

I was also told that EtOH is merely used after HCl to remove HCl from metal surface to prevent corrossion?
If this is the case, I shouldnt need to use HCl as my workbenches are not metal(altho I was told to wipe with these two chemicals no matter what the surface is).

We do not use RNAseAway in our lab as it is relatively costly.

Ethanol precipitates nucleic acid, just like it does in a DNA/RNA extraction. This does not remove the contaminating nucleic acid, though wiping will get rid of some of it. Ethanol will also precipitate proteins and things containing proteins (e.g. bacteria, skin cells) so that they are no longer a problem for contact contamination.

HCl is probably used to precipitate the protein in the virus as well. You would be better off using something that actually kills and removes the virus though, such as virkon or trigene.

But HCl will remove and degrade DNA and RNA. 0.1% doesn't sound as if it would do much, however. A 1% solution would probably be pretty effective, though.