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unc-22 nicotine test

Diana Janke collinse at sfu.ca
Fri Aug 22 12:07:32 EST 1997

Renaud Legouis <rlegouis at igbmc.u-strasbg.fr> writes:



>Can anybody tell me how to perform the 1% nicotine test for unc-22 
>heterozygotes? What is the type and source for nicotine?


>	Renaud

Here is the protocol for picking worms in nicotine as mentioned
in Moerman and Baillie 1979 (Genetics 91:95-103):

First, you want to use the 'free-base' version on nicotine- not the
salt.  The "free-base" is a liquid which can be diluted to 1% with
distilled water.

If you are just screening a few worms, what we generally do is
move the worms you want to screen to the edge of a 60mm petri-
plate (a bacteria-free area) and put a small drop of 1% nicotine
on the worms. If you are screening a whole plate, flood the plate with
about 1ml of the nicotine solution.  Wait a minute or so to give the
nicotine a chance to act, then screen the plate for "twitchers" under a
dissecting microscope set to 12-25 power.  The most noticable
twitching motion is in the head and tail.  All ages of worms
will twitch, but very gravid hermaphrodites don't twitch as well.
Wild-type worms become rigid in 1% nicotine. Pick the twitchers out of
the nicotine solution and move them to a clean, nicotine free plate
using a worm pick.  Try to do this as soon as possible as the worms are
not very happy in nicotine.

Please be warned that nicotine is a harmful substance to humans
as well.  Read up on the safety information before using it and
avoid sking contact and inhalation.

Hope this helps.

Diana Janke
Research Associate to David Baillie
Simon Fraser University
Burnaby, BC  Canada
djanke at darwin.mbb.sfu.ca

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