This assay assesses paralysis of C. elegans over a 2 hour period, scored every 10 minutes as moving or not moving.

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Aldicarb is extremely toxic and should be handled with care. Always wear gloves when handling aldicarb and aldicarb plates.

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Materials

• 1 mM aldicarb supplemented 6 cm NGM plates
• 4 copper rings (PlumbMaster #17668)
• Tweezers
• Bunsen burner
• Seeded 6 cm NGM plates
• OP50
• Microscope
• Timer
• 70% EtOH
• Worm pick

Advance preparation

1. Make aldicarb plates by adding 1 mL of 100 mM aldicarb stock to 100 mL of autoclaved, pre-cooled NGM.
   • To make the stock, mix 100 mg aldicarb into 5.25 mL of 70% EtOH for a 100 mM solution.
   • Store plates at 4°C for up to one month. Follow the Plate Pouring: NGM/HGM protocol to make and pour plates.
2. Pick 30 L4 stage worms of each strain of interest to seeded 6 cm NGM plates, 20–24 hours before the start of the assay.
3. Grow 5 mL of OP50 following the Plate Pouring: Growing OP50 protocol.

Protocol

1. On the morning of the assay, remove the 1 mM aldicarb plate from 4°C to acclimate to room temperature. Four strains fit onto one plate — remove as many plates as needed to run all desired strains. Label the bottom of the plate above the copper ring with a shortened version of the strain name.
2. Once the plate has warmed to room temperature, assemble the assay plates:
   • Ensure the copper rings lie flat on the bench — press them down flat until they do.
   • Spray the copper rings with 70% EtOH and flame them briefly using forceps or tweezers.
   • Quickly place the hot ring onto the aldicarb plate so that it embeds slightly into the agar.