can be flattened slightly with a hammer and then filed with

making it difficult to see or pick them. To pick a worm identified under the dissecting microscope， but this won't be a problem ifyou transfer animals before the plates reach that condition. If you do store your plates in a covered container be sure towatch for signs of high humidity. Although rare， and holdit there to allow the worm to crawl off of the picker. 4.2.Transferring frequency The frequency that you need to transfer your worms depends on their genotype， as it may accidentally be separatedfrom the bottom. Discarded plates should be placed in a plastic bag and autoclaved. ， most typically at 20 C. C. elegans grows 2.1 times faster at 25 C than at 16 C， andwhat you plan to do with them. Heterozygotes and mating stocks should be transferred every 1-3 generations; it is easier totransfer them if you do it before the plates have become starved. If you want to transfer individual animals from a starvedplate you may find it easier to first chunk the plate and then to pick individual animals after they have crawled out of thechunk and into the bacterial lawn. If the animals are in the dauer stage (see Genetic mapping and manipulation-Introduction and basics) you may need to wait a day before picking; the worms will develop out of the dauer stage， wrap it with a strip of Parafilm. Alternatively， wherein a sterilized scalpel or spatula isused to move a chunk of agar from an old plate to a fresh plate. There will usually be hundreds of worms in the chunk of agar.The worms will crawl out of the chunk and spread out onto the bacterial lawn of the new plate. This method works well fortransferring worms that have burrowed into the agar or are difficult to pick individually (such as on a starved plate). Thechunking method is fine for transferring homozygous stocks but it is not advisable if the population is heterozygous or ifa stock must be maintained by mating. Another method that will transfer many worms is to use strips of sterilized filter paper which have been cut to to inchwide and 2-3 inches long. The sterilized filter paper is gently set upon the petri plate， carefully wrap the plate with a strip of Parafilmand dispose of it. Do not take the cover off of a contaminated plate or you risk contaminating other plates. If you must transferfrom a contaminated plate。

temperature sensitivity or dauer defective) and maintain your stocks accordingly.Such information is included on the Strain Information Sheet that is sent with each strain shipped from the CGC. Stock plates do not need to be stored in a covered container. They will eventually dry out。

and 1.3 times faster at 20 C than at 16 C (). This variation in growth periods can be useful when planning experiments.