Worm Breeder's Gazette 1(2): 9a
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
Adults, larvae and eggs were washed off a large Petri plate with M9 salts and collected by centrifugation. Bacteria and worms were dissolved by incubating in a solution of 1-2% NaOCl and 0.5 N NaOH for 10 mins. at room temperature. The remaining purified eggs were collected by centrifugation (IEC clinical centrifuge, setting 3, 2 mins.) and washed 3 times with M9 salts. Ten thousand to 50,000 eggs per large Petri plate were obtained. Over 90% of the cleaned eggs hatched. Eggs can be purified further by centrifugation in a linear 5- 30% w/v sucrose gradient in the clinical centrifuge for 10 mins. at setting 3. Eggs reach equilibrium quickly and form a band in the middle of the gradient. When eggs of the temperature sensitive mutant, tsB73, are raised to 25 C, those eggs that are 7 hours or more prior to hatching develop into worms with a pear shape. Eggs that are passed this critical time develop into worms with wild type morphology. Purified tsB73 eggs were centrifuged to equilibrium in a 15-20% sucrose gradient in SW27 tubes. The gradient was collected and the eggs were plated at 25 C. The eggs of lighter buoyant density hatched first and 90% had wild type morphology. The eggs on the heavier side hatched later and were enriched for the pear morphology. Therefore, early embryos are heavier than later ones. This might be a useful method for staging embryos.