DNA ladder - (Mar/27/2006 )

what temperature do you keep DNA ladder (marker) at?
I just knew that it should be kept at -20C (it`s written on the specification) but my senior always keeps it at RT. no problem with that so far, though.
so, will the DNA ladder perform better if i always keep it at -20C?

Freezing and thawing all the time is not good. I always make aliquots and keep one of them in the fridge and the rest in the freezer. It is also possible to keep it at RT, but if there is some DNase in it, you will see it after some time.

We always keep our ladder at 4°C- no problems with that. You won't have to freeze/thaw it that way.

I do as Aspergillie does :
I make frozen aliquotes and keep one at RT.

You could also keep it at 4°C. however, the advantage of aliquoting is that you won't contaminate all your standard if you do a mistake.