Zamanian Lab C. elegans recipes.

M9 buffer (4X stock)

Reagent Amount for 4 L
KH₂PO₄ 48 g
Na₂HPO₄ 96 g
NaCl 80 g
MQ H₂O up to 4 L
  1. To make 4 L of 4X stock, measure all reagents into 3 L milliQ water in a 6 L flask and fully dissolve. Split the volume into two 2 L graduated cylinders and bring each to 2 L. Combine in the 6 L flask and aliquot into eight 500 mL aliquots.
  2. Autoclave on liquid cycle for 1 hour. Loosen the cap only a little, to maintain final volume.
  3. When the M9 is cool, add 2 mL of sterile 1 M MgSO₄ per 500 mL of M9 buffer.

Use autoclaved 2 L water bottles (1500 mL) to dilute to 1X for use in assays.

MgSO₄, 1 M (for M9 and S Medium)

  1. To make 500 mL, completely dissolve 123.24 g of MgSO₄ heptahydrate (FW 246.48) in 450 mL milliQ water from the carboy. Transfer to a graduated cylinder and bring up to final volume.
  2. Autoclave for 1 hour.

Potassium phosphate buffer, 1 M pH 6 (for S Basal/Medium and freezing solution)

Reagent Amount
KH₂PO₄ 136.1 g
KOH 17.99 g
MQ H₂O up to 1 L

Autoclave for 1 hour. Store in 500 mL aliquots.

S Basal

Reagent Amount
NaCl, 5 M 20 mL
Potassium phosphate buffer, 1 M pH 6 50 mL
Cholesterol, 5 mg/mL in ethanol 1 mL
MQ H₂O 930 mL

Autoclave on liquid cycle for 1 hour. The solution will be cloudy.

K medium

Reagent Amount
NaCl, 5 M 5.1 mL
KCl, 1 M 16 mL
CaCl₂, 1 M 1.5 mL
MgSO₄, 1 M 1.5 mL
MQ H₂O 500 mL
  1. Mix the pre-autoclaved salts above.
  2. Filter sterilize using a 0.22 μm filter.