>Because of the sort of presumed spontaneous mutation that Leon describes
>below, your OP50 and his and mine may all be different.
Creg is quite correct. Furthermore, in some experiments the food
genotype can make a huge difference. We routinely use two E coli
strains in the lab: DA837, a derivative of OP50 that I isolated and
froze several years ago, and HB101, which at one time was a standard
cloning strain. DA837 is harder for worms to eat than HB101.
Wild-type worms grow almost as well on DA837 as on HB101, but some
mutants show enormous differences. Worms with an eat-5 null mutation
(ad1402), for instance, are almost incapable of growing on DA837, but
grow essentially normally on HB101. This difference is so strong
that some members of the lab are using eat-5 as a selectable
cotransformation marker.
--
Leon Avery (214) 648-4931 (voice)
Department of Molecular Biology -1488 (fax)
University of Texas Southwestern Medical Center
6000 Harry Hines Blvd leon at eatworms.swmed.edu
Dallas, TX 75390-9148 http://eatworms.swmed.edu/~leon/
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