From owner-celegans@net.bio.net Mon Sep 26 23:00:00 1994 Newsgroups: bionet.celegans Path: biosci!bcm!cs.utexas.edu!howland.reston.ans.net!vixen.cso.uiuc.edu!usenet.ucs.indiana.edu!cottonwood.bio.indiana.edu!user From: macmorri@bio.indiana.edu (Peg MacMorris) Subject: Re: Worm diet Message-ID: Followup-To: bionet.celegans Sender: news@usenet.ucs.indiana.edu (USENET News System) Nntp-Posting-Host: cottonwood.bio.indiana.edu Organization: Dept. of Biology, Indiana University References: <9409240347.AA26191@synapse.bms.com> <362kd8$ei5@news.mic.ucla.edu> Date: Tue, 27 Sep 1994 14:51:57 GMT Lines: 30 In article <362kd8$ei5@news.mic.ucla.edu>, Ron Kagan wrote: > > In article <9409240347.AA26191@synapse.bms.com> Richard Belval, > belval@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@bio.indiana.edu Indiana University Bloomingtion, IN 47405 .