[Histonet] pepsin powder expiration date

[Gudrun Lang]

Dear histonetters,

We have a sigma pepsin powder (7012) in use for our FISH protocol. The
container has to be stored at -20°C, but has no labelled expiration date.

We have been using the same container for the last 18-20 months. Now we have
some troubles with the performance of our FISH-signals.

 

My question is for those, you have experience with this kind of product: 

How long can such pepsin powders be used without lost of activity?

 

Thanks in advance

Gudrun Lang

 

Histolab, Austria