GE PhastSystem User Manual page 94

Trouble Shooting Guide
Symptoms
PhastGel electrophoresis
Gels curls and/or
craks after drying
Protein
bands fade
after storage
Silver staining
Dark yellow
or brown
background
10
Probably Cause
No (or too little) glycerol in the (pre-
serving) solution.
1. Too much glycerol in the last
(preserving) solution.
2. The gel was exposed to direct
sunlight for an extended period.
1. The developer solution is too old,
or it contains too much formalde-
hyde.
2. The developer step temperature is
too high.
3. The glutardialdehyde
centration is too high.
Solution(s)
Rehydrate the gel in glycerol: acetic
acid: water according to Develop-
ment Technique Files. Dry it again.
Store the dried gel in a plastic slide
holder, or cover the gel again with
the protective film you removed
prior to separation.
1. Do not add more than 10%
glycerol.
2. Store the gel in a fairly dark place
e.g. a notebook.
1. Use fresh developer. Check the
concentration of the formal-
dehyde. The optimal concentra-
tion is 0.04% of 37% aqeous
formaldehyde, i.e. really 0.015%
formaldehyde in solution.
con-
2. The optimal temperature for this
sensitive step is 30°.
3. The optimal concentration is
8.3% in solution.