Degraded cDNA after freezing - (Feb/06/2002 )

RNA isolation from immunohistochemically stained frozen tissues (Chomczynski) with subsequent RT-PCR works well.
However, after freezing of cDNA the PCR doesn`t work anymore.
There is no cDNA detection anymore.

any suggestions?

(Edited by Mathias Droll at 6:54 pm on Feb. 5, 2001)

(Edited by Mathias Droll at 6:56 pm on Feb. 5, 2001)

I'm thinking freezing alone could not do this. I sure have never had a problem like this. I freeze my reactions in -20 C. It must be something other than the freezing. Have you solved the problem?

hi,
I made another  RNA Isolation + cDNA .
I put one part in the  -20°C freezer and another part in the 4°C Refrigerator.
The next day I made a PCR.
The PCR with the 4°C DNA works fine but the PCR with the -20°C PCR had no results :(

(Edited by Mathias Droll at 5:12 am on Feb. 9, 2001)