Taq Polymerase storage conditions - (Nov/08/2006 )

We are using Eppendorf HotMaster Taq DNA Polymerase in our qRT-PCR reactions. Last week we defrosted our -20C freezer and kept our taq at -80C overnight.

This week our runs are not working properly. Some runs have no amplification at all, others have 'junk' peaks, which appear as our typical primer dimer peaks appear. The melt curves confirm that this is not our sample that is being amplified.

My question is this - does anyone know if Taq polymerase degrades at lower temperatures? I had never heard of this, but it was suggested that maybe it could.

Did your tube of taq completely freeze?

If it froze, then there might not have been enough glycerol to keep it from freezing.
A lot of the time enzymes cannot be completely frozen. This is why the glycerol is there.

Hopefully that helps.

KIM