Hi Derek,
Is it possible that the blue color was due to Coomassie that was
tightly bound to the protein (perhaps in a colorless form) and released
during tryptic digestion? Would you get the same effect if you digested
protein that had never been treated with Coomassie?
Daniel
At 7:47 AM -0500 3/14/01, Derek Bradley wrote:
>Hi everybody,
>
>I've just completed a tryptic digest where the addition of the trypsin
>turned the digestion solution dark blue, I've been told that this sort of
>reaction can happen where there are particularly high concentrations of
>certain amino acids - apparently in this case tryptophan. I'm intrigued,
>can anyone expand on what exactly is going on for me?
>
>The gel piece was initially stained with coomassie, I destained it with 40%
>ethanol in 50mM amm. bicarb. and then washed it with 25mM amm. bicarb.,
>dehydrated with acetonitrile and then added the trypsin in 25mM amm. bicarb.
>
>Thanks,
>
>Derek Bradley
>Dept. of Medicine
>UCL
Daniel Wellner, Ph.D.
Department of Biochemistry
Weill Medical College of Cornell University
New York, NY 10021
This archive was generated by hypermail 2b29 : Mon Apr 02 2001 - 10:20:49 EDT