Worm diet

[Peg MacMorris]

In article <362kd8$ei5 at news.mic.ucla.edu>, Ron Kagan
<rkagan at ewald.mbi.ucla.edu> wrote:
> 
> In article <9409240347.AA26191 at synapse.bms.com> Richard Belval,
> belval at SYNAPSE.BMS.COM writes:
> >Do C. elegans feed off of autoclaved E. coli OP50
> >just as well as living E. coli OP50?
> 
> I have a related question:
> 
> How about OP50 cells that have been stored frozen?  I've always used
> fresh cells, but it has occurred to me that life would be easier if I
> could freeze down a bunch of pelleted OP50 cells for later use with
> liquid cultures of Nematodes.  Has anyone tried this?
> 
We routinely store pellets of frozen E. coli (NA22) and use them to feed
worms in liquid culture.  We grow a large fermenter batch of E. coli and
then harvest and freeze the bacteria in weigh boats.  The greatest problem
is that the apparatus and procedure we use for harvesting are not designed
for maintaining sterility of the cultures.  Therefore, it is easy to
introduce contaminating microbes to worm cultures, although the greater
biomass is E.coli.  Again that is not such a problem, especially if the
liquid culture is to be harvested for a large biochemical prep as opposed
to subsequent culturing. 
--
Peg MacMorris         Voice: (812) 855-0102                     
Dept. of Biology                Fax: (812) 855-6705                     
Jordan Hall                Internet: macmorri at bio.indiana.edu 
Indiana University                                                      
Bloomingtion, IN 47405