Barbara,
Have you tried picked the blue colonies straight off of the
plates? I have had reasonable success doing so. Two obvious caveats,
1) you don't want the plates too dense to avoid picking the neighboring
colonies 2) You have to pick the colonies off of the filters (within 36
hours or so).
Guy Oshiro
EMAIL: Oshiro_G at defiance.hsc.colorado.edu
/\ /\ /\
/ \/ \/\/ \ Science in the Rockies.
/ \ \/ \