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BAM Media M1: A-1 Medium

January 2001

Bacteriological Analytical Manual

A-1 Medium

Tryptone 20 g
Lactose5 g
NaCl5 g
*Triton X-100 (Rohm & Haas)1 ml
Salicin0.5 g
Distilled water1 liter


Dissolve ingredients in 1 liter distilled water. Adjust pH to 6.9 ± 0.1. Dispense 10 ml portions of single strength broth into 18 x 150 mm tubes containing inverted fermentation vials. For double strength broth, use 22 x 175 mm tubes containing inverted fermentation vials. Medium may be cloudy before sterilization. Autoclave 10 min at 121°C.


Store in dark up to 7 days.

(Commercially available A-1 medium is unacceptable)

Storagedark, up to 7 days

*Triton X-100 may be purchased from Fisher Scientific Company, Fairlawn, NJ 07410.


Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.