CRITERION™ Sterility Test Broth

Cat. no. C7610 CRITERION™ Sterility Test Broth 58gm
Cat. no. C7611 CRITERION™ Sterility Test Broth 500gm
Cat. no. C7612 CRITERION™ Sterility Test Broth 2kg
Cat. no. C7613 CRITERION™ Sterility Test Broth 10kg
Cat. no. C7614 CRITERION™ Sterility Test Broth 50kg


Hardy Diagnostics CRITERION™ Sterility Test Broth, or USP Alternative Thioglycollate Medium, is recommended for the cultivation of microorganisms and determining the presence of bacteria in sterile materials. The medium is described in the U.S. Pharmacopeia National Formulary (USP) for sterility testing turbid or viscous materials.(3)

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


Sterility Test Broth, also known as USP Alternative Thioglycollate Medium, is a Fluid Thioglycollate Medium lacking agar or an oxygen indicator. Sterility Test Broth meets the USP growth promotion testing requirements and is intended for sterility testing biological products that are turbid or highly viscous and that cannot be cultured by traditional FTM or Thioglycollate Media.(3) Sterility Test Broth is to be used under the same sterility testing procedures as traditional FTM; however, incubation of specimens occurs under anaerobic conditions, rather than aerobically.

CRITERION™ Sterility Test Broth contains sodium thioglycollate as a reducing agent, which prevents the formation of toxic peroxides that may be lethal to certain microorganisms, and helps to maintain low oxygen tension by removing molecular oxygen from the environment. L-cystine and casein supply carbon and nitrogenous compounds; L-cystine also functions as a reducing agent to support anaerobiosis. Dextrose is added as an energy source, and sodium chloride provides essential ions and helps maintain osmotic equilibrium.


Gram weight per liter: 29.0gm/L
Casein Peptone 15.0gm
Dextrose 5.5gm
Yeast Extract 5.0gm
Sodium Chloride 2.5gm
L-Cystine 0.5gm
Sodium Thioglycollate 0.5gm

Final pH 7.1 +/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.


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 light beige

Store the prepared culture media at 15-30ºC. in the dark.



1. Suspend 29gm of the dehydrated culture media in one liter of distilled or deionized water. Stir to mix thoroughly.

2. Heat as necessary to dissolve completely. Do not overheat.

3. Dispense into desired containers.

4. Sterilize in the autoclave at 121ºC. for 15 minutes.


For information on procedures and interpretation of results, consult listed references.


This medium lacks agar and a reducing indicator. Therefore, it is recommended that the medium be prepared just prior to use to ensure an atmosphere suitable for the growth of anaerobic microorganisms. Long term storage of the prepared medium is not recommended. However, autoclaved volumes of Sterility Test Broth should be held at 15-30°C in the dark, since storage of the prepared medium at lower temperatures increases oxygen absorption.

Prepared volumes of Sterility Test Broth should not be reheated more than once prior to use, due to the formation of toxic oxygen radicals that may form upon repeated reheating.


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


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Clostridium novyi
ATCC ® 7659
J 1-7days 35°C Aerobic Growth
Staphylococcus aureus
ATCC ® 25923
J 1-7days 35°C Aerobic Growth
Candida albicans
ATCC ® 10231
J 1-7days 35°C Aerobic Growth
Bacillus subtilis
ATCC ® 6633
J 1-7days 35°C Aerobic Growth

User Quality Control

Physical Appearance

CRITERION™ Sterility Test Broth powder should appear homogeneous, free-flowing, and light beige in color. The prepared medium should appear clear, and yellow in color.


1. N.I.H. 1955. Memorandum: Culture Media for Sterility Tests, 4th Revision.

2. The Official Compendia of Standards. 2008. USP27-NF22. United States Pharmacopeial Convention, Rockville, MD.

3. United States Pharmacopoeia and National Formulary (USP-NF). Rockville, MD: United States Pharmacopeial Convention.

ATCC is a registered trademark of the American Type Culture Collection.