M17. Brain Heart Infusion (BHI) Agar (0.7%) (for staphylococcal enterotoxin)
Prepare a suitable quantity of brain heart infusion broth. Adjust pH to 5.3 with 1 N HCl. Add agar to give 0.7% concentration. Dissolve by minimal boiling. Dispense 25 ml portions into 25 x 200 mm test tubes. Autoclave 10 min at 121°C.
M18. Brain Heart Infusion (BHI) Broth and Agar
Formulations used by selected manufacturers are represented below; these media are normally available as pre-mixed dry powder.
Medium 1 Calf brain, infusion from 200 g Beef heart, infusion from 250 g Proteose peptone (Difco) or polypeptone (Bioquest) 10 g NaCl 5 g Na2HPO4 * 2.5 g Dextrose 2.0 g Distilled water 1 liter
Medium 2 Brain heart-infusion 6.0 g Peptic digest of animal tissue 6.0 g NaCl 5.0 g Dextrose 3.0 g Pancreatic digest of gelatin 14.5 g