From owner-drosophila@net.bio.net Sat May 20 23:00:00 1995
Path: biosci!agate!sunsite.doc.ic.ac.uk!daresbury!imbb1.imbb.forth.gr!nefeli.imbb.forth.gr!DELIDAKIS
From: delidakis@nefeli.imbb.forth.gr
Newsgroups: bionet.drosophila
Subject: help with food
Date: Mon, 22 May 1995 02:41:14 GMT
Organization: Imbb-forth,CREtE, creece
Lines: 29
Distribution: world
Message-ID: <00990B43.AE0B4C85@nefeli.imbb.forth.gr>
Reply-To: delidakis@nefeli.imbb.forth.gr
NNTP-Posting-Host: nefeli.imbb.forth.gr

Dear Drosophilists

The fly group in the IMBB is facing a serious food problem and we'd be very
greatful if you had any suggestions on how to solve it. Basically, our 
food works fine if the stock/cross is healthy and we put a good number
of females per vial (6-8 rather than the 1-2 suggested in Kathy Matthews'
recent posting). However, when we go down to 1-3 females of a not so
vigorous strain, the culture becomes overrun by some sort of slime, which
is probably bacteria. A few eggs and 1st instar larvae are usually seen
dead in the slime. The only way to prevent this infection is to add
tetracyclin in the food (final concentration 1 ug/ml), but I was wondering
if there was a solution that doesn't involve the use of antibiotics. So,
if you have any modifications on the following recipe, we'd like to try them:

Per 3 litres of water we use:
70 g  sugar (sucrose)
170 g  yeast (baker's yeast cake previously autoclaved to make sure it's
	dead)
30 g  agar
200 g  cornflour
+ 50 ml of 10% Nipagin (0.17% final)

The food is usually used fresh (<4 days after cooking - meanwhile stored
in the coldroom).

Thank you for your help
Christos Delidakis
Inst. of Molecular Biology & Biotechnology
Heraklion, Greece

.