 |
 |
 |
by Michael Koelle
4/6/94
There are two kinds of contaminants on worm plates:
1. Fungi: these contaminants can come from the plates or bacteria, so it is best to leave plates out after seeding for a couple of days to make sure no fungal colonies grow before adding worms. If a stock gets fungus, just transfer the worms regularly from parts of the plate away from the fungi; the worms will outgrow the fungus.
2. Non-OP50 bacteria ("slime"). No amount of transferring the worms will cure this. To decontaminate worms, make ~12% NaOCl, 1.5 M NaOH, and add a drop to the unseeded portion of a fresh plate. Place ~10 gravid adults in the drop. Can recover a strain from a single adult if necessary. The adults and bacteria will die; the eggs will live. Leave the plate right side up overnight; the drop of liquid will be absorbed, and live hatched worms will crawl onto the bacterial lawn. It is necessary to move the hatched larvae to a new plate the next day; after that bacteria and fungus generated from resistant spores will spread over the plate and recontaminate the worms. Alternatively, a flamed spatula can be used to slice off and remove the discolored portion of the plate where the NaOCl/NaOH drop was.
|
|
|
|
This file was converted with TextToHTML - (c) Logic n.v.