Trial #2 - feeding begins

Snail-targeting and control E. coli strains were grown overnight at room temperature with aeration, in 1L flasks containing 240ml LB, ampicillin 0.1mg/ml, tetracycline 0.01mg/ml, IPTG 1mM, to OD600~1.0 (roughly approaching a billion cells per milliliter). Cultures were spun down (3000 x g, 10 minutes at 4C), resuspended in 1 volume H2O, and heat-inactivated by addition of equal volume near-boiling 2% agar followed by 45 minute incubation at 55C. That was yesterday. This evening, six pairs of young adult B. glabrata (pulled out of all-you-can-eat romaine lettuce buffet) were each placed in 3L artificial pondwater in a Sterilite shoebox, and given ~1.5g of gelled bacteria-suspension, with a piece of chalk as a calcium supplement. We shall come back in a few days and see what happens. Encouragingly, one snail started eating on the bacteria-agar chunk immediately. This stuff is about 25% E. coli by volume. I have meanwhile done plasmid minipreps and planned restriction digests, in order to be absolutely sure the cells have the right DNA in them. Frozen cells (both snail-targeting and control, from cultures before and after induction) are set aside for RNA extraction too, just to see the bands on a gel.