|Tryptose or polypeptone||10.0 g|
|Thiopeptone or thiotone||5.0 g|
|Casitone or trypticase||5.0 g|
|Yeast Extract||1.5 g|
|Sodium chloride, NaCl||5.0 g|
|Dipotassium hydrogen phosphate, K2HPO4||4.375 g|
|Potassium dihydrogen phosphate, KH2PO4||1.375 g|
|Sodium lauryl sulfate||0.05 g|
|Sodium desoxycholate||0.10 g|
|Sodium sulfite, Na2SO3||2.10 g|
|Basic fuchsin||1.05 g|
|Agar (optional)||15.0 g|
|Reagent grade water||1 L|
Agar preparation – Rehydrate all product in 1L water containing 20 mL 95% ethanol. Heat to near boiling to dissolve agar, then promptly remove from heat and cool to between 45 and 50°C. Dispense 5- to 7- ml quantities into 60-mm sterile petri dishes. If any other size petri dish is used, adjust quantity to give an equivalent depth. Do not sterilize by autoclaving. Final pH should be 7.2 ± 0.2. A precipitate is normal in Endo-type media.
Refrigerate finished medium in the dark and discard unused agar after 2 weeks.
Broth preparation – Prepare as above, omitting agar. Dispense liquid medium (at least 2.0 mL per plate) onto absorbent pads (see Standard Method for Examination of Water and Wastewater, 2012, 22nd ed., section 9222B.1 (h) for absorbent pad specifications) and carefully remove excess medium by decanting the plate, the broth may have a precipitate but this does not interfere with medium performance if pads are certified free of sulfite or other toxic agents at a concentration that could inhibit bacterial growth. Refrigerated broth may be stored up to 4 days.
* Dehydrated Difco M-Endo MF (# 0749), dehydrated BBL m-Coliform Broth (# 11119), or equivalent may be used if absorbent pads are used.