Hi Lowell,
In the 70's we used George Stark's method for blocking lysines with sodium
cyanate followed by tryptic digestion to limit the number of spots by 2D
thin layer. True, the reaction isn't reversible, but might be a little
better for in-gel modification due to its high reactivity. We routinely get
essentially quantitative reaction by including a reduction/alkylation step
in the first coomassie extraction of the gel slice. It shouldn't be much of
a trick to include cyanate in the second wash step. This minimizes
extractive losses due to washout. Of course you should take the usual
precautions with cyanate, don't work outside of a hood, and keep the pH
around 8. I did this a lot and it didn't affect me, affect me, affect me.
regards
>
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Gary M. Hathaway, Director
PPMAL - Protein/Peptide Micro Analytical Laboratory
California Institute of Technology
139-74, Division of Biology
Pasadena, CA 91125
http://www.cco.caltech.edu/~ppmal
email Gary: hathaway@caltech.edu
email facility: ppmal@caltech.edu
phone: lab (818) 395-6388 or office (818) 395-2769
FAX (818) 449-3414
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