OP50 follow up

[Creg Darby]

If you need a selectable marker in OP50 and aren't fussy about which
antibiotic, the easiest course is to select a spontaneous
Streptomycin-resistant mutant. Point mutations in the chromosomal rpsL
gene in E. coli give high levels of resistance, with no other annoying
phenotypes, and they're trivial to make: Plate an overnight culture on 100
micrograms/ml of Strep and pick colonies for purification the next day. 

The advantage of this marker is that it's chromosomal, hence very stable:
You needn't propagate the strain on Strep to preserve the marker.

You can also get spontaneous Rifampicin resistance easily, but Rif is more
of a nuisance to work with.

Creg Darby                                     cdarby at u.washington.edu
Department of Genetics                              
Box 357360                                           lab: 206-543-9446
University of Washington                             
Seattle, WA 98195                                    fax: 206-543-0754


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Creg Darby                                     cdarby at u.washington.edu
Department of Genetics                              
Box 357360                                           lab: 206-543-9446
University of Washington