We use OP50 and notice 2 problems. One, we get "dots" of abnormal
colonies within the main lawn. Two, every once in a while the OP50 is
a fast growing mass that has a thick crusty look to it rather than
being a loose colony. We've done everything we can think of to resolve
these problems, like constantly streaking new colonies for our LB,
making smaller portions of LB so the OP is not very old (2 months),
sterilizing any tools, and ordering new stock from the elegans
center.
Have others had this problem? Is this most likely a contamination
problem, or can the OP just be accumulating common mutations that
result in this phenotype?
The problem with this stuff is that with this crusty bacteria, it
pellets with the worms and can't be separated.
TIA
