Cat. no. C8070 CRITERION™ Tryptose 100gm
Cat. no. C8071 CRITERION™ Tryptose 500gm
Cat. no. C8072 CRITERION™ Tryptose 2kg
Cat. no. C8073 CRITERION™ Tryptose 10kg
Cat. no. C8074 CRITERION™ Tryptose 50kg


Hardy Diagnostics CRITERION™ Tryptose is recommended for use in the preparation of culture media for microbiological purposes.

This is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.


The original use for tryptose was as a peptone specifically used to enhance the growth of Brucella. CRITERION™ Tryptose may be used in concentrations of 0.1% to 10% for the cultivation of organisms such as Brucella, streptococci, meningococci, and pneumococci. This peptone has been shown to result in better growth of these organisms than previously used meat infusion peptones. Huddleson found that a broth made with tryptose was equal or superior to meat infusion media, providing uniformity for the cultivation and differentiation of fastidious organisms.(1)

For the microorganism Bordetella bronchiseptica, the most productive phosphatase activity at 37°C was found in Tryptose Broth.(2) Tryptose Broth is also useful for the isolation of Brucella from blood. Castaneda studied the isolation of Brucella species using a broth containing 2% Tryptose and 2% sodium citrate.(3) In this case, sodium citrate served as an anticoagulant and assisted in inactivating complement in the blood specimen.

CRITERION™ Tryptose provides peptones, nitrogen, amino acids and vitamins to facilitate growth. Addition of 0.1% agar to Tryptose Broth may increase growth of aerobes and anaerobes in liquid media.


Store the sealed bottle(s) containing dehydrated culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original tan.



Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.

Physical Appearance

CRITERION™ Tryptose powder should appear homogeneous, free-flowing, and tan in color.


1. Huddleson, I.F. 1943. Brucellosis in man and animals. Rev. Ed. The Commonwealth Fund, New York, NY.

2. Mobley, D.M., Chengappa, M. M., Kadel, W.L. and J.G. Stuart. 1984. Effect of pH, Temperature and Media on Acid and Alkaline Phosphatase Activity in "Clinical" and "Nonclinical" Isolates of Bordetella bronchiseptica. Can. J. Comp. Med.; 48:175.

3. Castaneda, M.R. 1947. A practical method for routine blood cultures in brucellosis. Proc. Soc. Exp. Biol. Med.; 64:114-115.

4. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.

5. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

6. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.

7. The Official Compendia of Standards. 2008. USP 27, NF 22. United States Pharmacopeial Convention, Rockville, MD.

8. U.S. Food and Drug Administration. Bacteriological Analytical Manual. AOAC, Arlington, VA.