Stephen Lessnick <stevel at ucla.edu> wrote:
>1) Why would one expose 35S sequencing gels at -70 degrees in the first
>place since they don't possess enough energy to make the enhancing screen
>worthwhile. On the other hand, soaking the gel in salicylate or PPO
>would provide the enhancement effect, and then I believe it would make a
>difference to expose the gel at -70.
>Use of a screen is not the only reason to expose at -70. The film
emulsion itself retains an image better at -70. Thus irrespective of
whether or not a screen is used, there is advantage to be gained by
exposing at -70.
John R. Thompson
Merck Research Labs