I’m doing a starvation experiment and I want to be able to pick up worms without using OP50 as the “glue”, as this introduces food onto the plate. Can anyone recommend a substitute for OP50 that doesn’t have nutrients? I can pick up a few worms at a time with using OP50, but it gets tedious to try to look at numerous worms. Thanks!
You could use a flat pick instead of the rounded one, this helps. Also make sure you pick worms off of food. You could also move worms into M9 in a two well slide, then to the next well of the two well slide and then onto the plate without food, all using a flattened pick. We use these flattened picks quite often when we are doing dissections for IF.
We pick without food for behavioral assays all the time. The best way is to use a good, flat pick, press it down slightly on the agar, and get UNDER the worm. Picking the worm up in this way allows you to then set it down on the assay plate, again by pressing the pick slightly onto the surface. The little bit of liquid that comes up when you press the pick down to set the worm down will help it to swim off the pick. Just be careful that you don’t poke any holes in the agar or nick the surface of your assay plate as you gently set the worm down. Marking up the plate you’re picking from isn’t a problem, and it usually happens so that you can easily get the pick under the worm without damaging it in any way. It is tedious, because you can only move one worm at a time, but it works well. Note - in this way the worm is always on the TOP of the flat surface of the pick. And, because you don’t have any food there, the worms will dry out quickly - so you do need to be careful that it doesn’t take too long to move it to the new plate.
You can try a truncated eyelash pick. Truncate the end of an eyelash so that it’s about as thick as a platinum pick, and glue or white-out the eyelash to a glass pipette, and use it like a regular pick. Before you pick up worms dip just the eyelash end in 95% ethanol to sanitize. You might have to get used to picking up worms with the eyelash, the disadvantage is you can “fling” the worm and it’s best not to maintain strains with the eyelash due to the chance of contamination. For lifespan experiments it is very useful though, because you can avoid picking up any food, and because the eyelash is made of a lot of protein, worms don’t get injured on the eyelash as often, nor are they at as much risk of dehydrating on the eyelash as they are on platinum picks.