Bleaching to Clean Worms

Removing Bacterial Contamination

  1. Chunk a ~1 cm2 area from the contaminated plate to a labeled 6 cm plate.

  2. After 1-2 days, place 15 μL of bleach solution (recipe below) at the edge of a new, labeled 6 cm plate (as far from bacteria spot as possible).

  3. Place a minimum of ten gravid animals into the bleach (up to 20 animals is good). The bleach should dissolve the cuticle of the adult worms, releasing the embryos. Leave the plate lid-side up until all the bleach has soaked into the plate. After the bleach has soaked in, move the plate, lid-side down, to the optimal temperature for the worms.

    Note: You can add a little more bleach (~10 μL) after you place the adults if some of the initial bleach absorbed into the plate.

  4. After ~24 hr., move L1s from the bleach plate to a clean, labeled 6 cm plate. You want between 10-20 L1s per plate - the more the better. If you think you will need this strain a lot, pick 10-20 L1s to multiple plates.

Removing Mold Contamination

  1. Chunk a ~1 cm2 area from the contaminated plate to a labeled 6 cm plate.

  2. After 10-30 min., pick 20-30 animals to a new, labeled 6 cm plate.

    Note: If the original contaminated plate is more than a month old, chunk a larger chunk (5 cm2) to the new plate to increase the likelihood of transferring live worms. It might take longer (up to 24 hr.) for the worms to crawl from the chunk to the new plate.

  3. If there was a lot of contamination, you might want to repeat steps 1 and 2 to allow the worms a second chance to crawl away from the mold.

Bleach Solution

Bleach solution should be stored at 4°C.

Reagent Amount Needed
NaOCl (from Fisher, cat #SS290-1) 2 mL
10 M NaOH* 0.5 mL
dH2O up to 10 mL

*can also use 0.2 g NaOH pellets per 10 mL of total bleach solution.