How to Make Cholesterol

Note: C. elegans requires cholesterol to progress through the four larval stages. The Andersen lab found that some filters were removing cholesterol from K medium and S medium. Most worms arrested in larval development. For this reason, we add cholesterol after filtration or autoclaving of media for NGMA plates.

For NGM/HGM plates: Use the unfiltered but sterile 5 mg/mL cholesterol in ethanol.

To make this cholesterol,

  1. Take an autoclaved sterile 250 mL bottle.

  2. Add 1 g of powdered cholesterol (VWR Cat #0433-250G) to the bottle.

  3. Add 200 mL of 100% ethanol to the bottle.

  4. Cap and shake to resuspend.

  5. Store at room temperature on the reagents shelf for up to six months.