Acrylamide Gel setting too quickly -- IDEAS??

[Michael Szardenings]

In article <6ACvwePc0LB at gunhill.swb.de>, reish at gunhill.swb.de says...
>
>michelle quoted on 02.06.96:
>
>> On Sat, 1 Jun 1996, Brian MacNevin wrote:
>>
>> >     My first thought is that this might be due to the temp of the
>> > solution.  It seems to me that I don't have this problem if the
>> > solution is allowed to cool a little before adding the final solution.
...
>> Yes, it is definitely the temperature.  Acrylamide gels always take
>> longer to set on cold days.  Try chilling the acrylamide mix before adding
>> the TEMED and  APS until it feels cool to touch.  Also, don't use high heat
>> to dissolve the urea.  
...
>It's also helpful to put the glassplates in the fridge for about fifteen  
>minutes.

DON'T DO THIS when preparing a sequencing gel! The urea will crystallize. 
Although I agree, that its usually the temperature, one should not forget, 
that there might be differences caused by the 'age' of both TEMED and APS. So 
if I tell you, that I generally use 60 myl TEMED and 400myl 10% APS per 100ml 
sequencing gel solution (6%), this does not mean, that it will work for you 
perfectly. Degassing the solution and treatment with ionexchanger can also 
speed up the polymerisation.
no alligators, moose !
			Michael
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