Culture Preservation

[Stephen_W._Mamber_at_~PRIWFB05 at ccmail.bms.com]

     My favorite general purpose cryopreservation method is the following, 
     from D. Maron/B. Ames, Mutation Research 113:173-215, 1983 
     (Salmonella/Ames test):  To 8 ml late-log or stationary-phase cells in 
     media, add 0.7 ml DMSO (less than 10%).  Mix and freeze.  This 
     definitely works for Gram-negatives (enterobacteriaceae), 
     Gram-positives (cocci) and yeast (Saccharomyces).  I don't know about 
     more fastidious organisms.  If you are worried about the sterility of 
     your DMSO you can filter it through 0.2 um teflon filters, but I 
     generally designate one bottle as 'clean' and remove aliquots with 
     sterile pipets.  SWM
     
     mamber at synapse.bms.com