From owner-celegans@net.bio.net Tue Mar 11 22:00:00 1997 Path: biosci!ihnp4.ucsd.edu!swrinde!howland.erols.net!cam-news-hub1.bbnplanet.com!su-news-hub1.bbnplanet.com!news.bbnplanet.com!arclight.uoregon.edu!news.bc.net!rover.ucs.ualberta.ca!elegans.biology.ualberta.ca!user From: a.manning@ualberta.ca (Angela Manning) Newsgroups: bionet.celegans Subject: removing worms from an agarose pad - a poll Followup-To: bionet.celegans Date: Wed, 12 Mar 1997 00:31:15 -0700 Organization: Genetics U of Alberta Lines: 53 Message-ID: NNTP-Posting-Host: elegans.biology.ualberta.ca Dear fellow worm breeders, There was a recent argument in our lab over the preferred method of removing worms from an agarose pad following microinjection. I am asking that people just email me directly with a response from the choices 'worm pick,' 'glass pipette,' or 'pipetman' (with no need for an accompanying explanation): maduro@odum.biology.ualberta.ca I shall post the results and descriptions of any other methods suggested. Method A: Removal by worm pick -------- A small drop of M9 (or 0.1 M NaCl) is added to the paraffin/halocarbon oil. The worms float off after a minute or so and are removed one at a time by passing a platinum pick under each one. Typical time: varies, say 5-10 seconds per worm, or 1.5 to 3 minutes for 20 worms. Typical recovery: depends on shape of worm pick and experience of user; can approach 95% of animals that survived injection Method B: Removal by pipette -------- I have been using a 10 ul Socorex pipetman to remove the worms. 10 ul of M9 or 0.1 M NaCl are pipetted onto the oil; the liquid is pipetted up and down to free the worms from the pad. After doing this two or three times, all of the worms (10-20) are pipetted up into the tip all at once. The worms are dispensed in one drop on the side of a seeded plate. Usually, many worms stick to the inside of the pipette tip: This can be remedied by just pipetting up and down, using the meniscus (and bits of paraffin oil) to free them. As an alternative, silanized pipette tips or a glass capillary and mouth pipet could be used (I haven't tried these). Typical time: 30 seconds for 20 worms. Typical recovery: routinely greater than 95% (of animals surviving injection). Thanks, Morris Morris Maduro (maduro@odum.biology.ualberta.ca) Dept of Biological Sciences University of Alberta Edmonton, AB Canada T6G 2H3 .