Cat. no. C5160 CRITERION™ BiGGY Agar 98gm
Cat. no. C5161 CRITERION™ BiGGY Agar 500gm
Cat. no. C5162 CRITERION™ BiGGY Agar 2kg
Cat. no. C5163 CRITERION™ BiGGY Agar 10kg
Cat. no. C5164 CRITERION™ BiGGY Agar 50kg


Hardy Diagnostics CRITERION™ BiGGY Agar (Bismuth Sulfite Glucose Glycine Yeast Agar) is a selective and differential medium used in the isolation and presumptive identification of Candida spp.

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.


BiGGY Agar was developed by Nickerson in 1953 following a study of sulfite reduction by Candida species. Nickerson found many yeast capable of reducing bismuth sulfite to bismuth sulfide when grown on an acidic or neutral medium containing the reducing substrate. Substrate reduction was noted by the production of brown to black pigmented colonies, a result of sulfide combining with bismuth.(1-7)

Bismuth sulfite inhibits bacterial growth, thereby enabling the recovery of isolated colonies of Candida. Candida spp. reduce the bismuth sulfite resulting in pasty brown to black colonies. Some Candida species present as brown to black colonies surrounded by zones of dark precipitate in the medium. Dextrose and yeast extract provide the nutrients in the formulation.


Gram weight per liter: 49.0gm/L
Dextrose 10.0gm
Glycine 10.0gm
Bismuth Ammonium Citrate 5.0gm
Sodium Sulfite 3.0gm
Yeast Extract 1.0gm
Agar 20.0gm

Final pH 6.8 +/- 0.2 at 25ºC.

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


Store the sealed bottle(s) containing dehydrated culture medium at 2-30 degrees C. 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 media in plates at 2-8ºC.



For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. G17.


Bacteria and yeast like fungi are mostly inhibited on this media, however, if break-through occurs they can be easily differentiated by microscopic examination.


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


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Candida albicans
ATCC ® 60193
A 24-72hr 15-30°C Aerobic Growth; smooth tan or brown to rust colonies, no diffusion of color
Candida krusei
ATCC ® 14243
A 24-72hr 15-30°C Aerobic Growth; flat wrinkled reddish-brown colonies, yellow diffusion of color in medium, silver sheen
Candida tropicalis
ATCC ® 750
A 24-72hr 15-30°C Aerobic Growth; smooth brown to black colonies
Escherichia coli
ATCC ® 25922
B 24hr 15-30°C Aerobic Partial to complete inhibition

User Quality Control


CRITERION™ BiGGY Agar powder should appear homogeneous, free-flowing, and light beige in color. The prepared media should appear opalescent with moderate precipitate evenly suspended throughout the medium, and slightly white in color.


1. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.

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

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

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

5. Larone, D.H. Medically Important Fungi: A Guide to Identification, American Society for Microbiology. Washington, D.C.

6. Nickerson. 1953. Journal of Infectious Diseases; 93:43.

7. Atlas, Ronald M. 1993. Handbook of Microbiological Media, CRC Press, Inc.

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