|Yeast extract||4 g|
|Distilled water||970 ml|
10% aqueous, filter-sterilized
On day of use, dissolve peptone, yeast extract, and NaCl in distilled water. Autoclave 15 min at 121°C. Cool. Add 30 ml freshly prepared, filter-sterilized NaHCO3, and mix. Dispense aseptically into screw-capped tubes (use 15 ml for 16 × 125 mm tubes). Final pH, 7.4 ± 0.2.
Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.