Wash one1 or several2 worm plates3 with milli-Q water4. Put the worms into a 1.7 mL Eppendorf tube5.
1 To wash a plate: Remove a small chunk of agar near the plate border (we use a metal spatula). Using the 1 mL pipette, add 1-2 mL of milli-Q water to the plate. Tilt the plate so that all the water is on the missing chunk side. Pipetting in the hole, take about 1 mL of water, and spray it on the plate to dislodge the worms. When spraying the water, point diagonally towards the plate, to prevent splashes. Do this several times, so that most worms accumulate at the bottom. Then take the water full of worms with the pipette, and put it in an autoclaved 1.7 mL Eppendorf tube. The agar absorbs some water, so if you initially put 2 mL you will get around 1.5 mL in the tube. You can repeat this procedure several times to get as many worms as possible, but unless you really need to get all of them one wash is usually enough.
2 We typically do this with as many as 8 plates at the same time with no issues (if you have many plates you will have a big worm pellet, and the bleaching may take slightly longer, but we have not found problems with it). To wash more than one plate, you can pellet the worms in the Eppendorf as indicated later, remove the supernatant and add the worms from the next plate to the same Eppendorf.
3 The plates should contain many hermaphrodites with eggs inside. With N2 worms and NGM+OP50 plates, this usually happens about 2 days after starting the plate. It’s very important that the plate has bacteria left. Once the worms deplete the bacteria, they lay their last eggs in a few hours, and don’t have eggs inside any more (and only the eggs that are inside worms at the beginning of the process survive the synchronization).
4 Sterile (autoclaved) milli-Q water.
5 Eppendorfs should be autoclaved before using them. Use clear (i.e. non-colored) Eppendorf tubes, so that you can see the worms inside.