Cat. no. C5390 CRITERION™ Yersinia Selective Agar (CIN) Base 119gm
Cat. no. C5391 CRITERION™ Yersinia Selective Agar (CIN) Base 500gm
Cat. no. C5392 CRITERION™ Yersinia Selective Agar (CIN) Base 2kg
Cat. no. C5393 CRITERION™ Yersinia Selective Agar (CIN) Base 10kg
Cat. no. C5394 CRITERION™ Yersinia Selective Agar (CIN) Base 50kg


Hardy Diagnostics CRITERION™ Yersinia Selective Agar (CIN) Base is recommended for use in the isolation and differentiation of Yersinia and Aeromonas species.(6,7)

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.


Yersinia enterocolitica has been well documented as a causative agent of gastrointestinal infections that invades the intestinal mucosa and lymph nodes. It is a major cause of enteric illness in the northern United States, Canada, and Europe. Y. enterocolitica infection may occur either sporadically, through food, or water-borne outbreaks. However, infections have been found at extraintestinal sites as well. Other Yersinia spp. have also been implicated as human pathogens, but are found less frequently than Y. enterocolitica.

CIN Agar, originally developed in 1979 by Schiemann, is a highly selective medium designed to isolate Yersinia enterocolitica . The properties of this medium are based on selective chemical agents, antibiotics, dyes, and the basal medium. It is highly selective against the growth of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enterica, Shigella sonnei, and Streptococcus faecalis.(6,7) The characteristic deep red center with a transparent margin, or "bull's-eye" appearance of Yersinia and Aeromonas colonies is important for identification, and is due to the presence of mannitol and sodium deoxycholate in the medium. Y. enterocolitica ferments the mannitol in the medium, producing an acid pH which gives the colonies their red color. The sodium deoxycholate is responsible for the "bull's-eye" phenomenon. It was demonstrated that by reducing the concentration of cefsulodin from 15.0 to 4.0mcg/ml, CIN Agar could also be used to selectively isolate Aeromonas spp., in addition to Yersinia.(8)

Studies have proved that CIN Agar is superior to SS (Salmonella-Shigella) Agar and MacConkey Agar in recovery rates of Y. enterocolitica from clinical specimens and food sources.(7)


Gram weight per liter: 59.5gm/L
Mannitol 20.0gm
Peptone 17.0gm
Proteose Peptone 3.0gm
Yeast Extract 2.0gm
Sodium Pyruvate 2.0gm
Sodium Chloride 1.0gm
Sodium Deoxycholate 0.50gm
Sodium Cholate 0.50gm
Neutral Red 30.0mg
Magnesium Sulfate 10.0mg
Irgasan ® 4.0mg
Crystal Violet 1.0mg
Agar 13.5gm

Final pH 7.4 +/- 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 pinkish-beige.

Store the prepared culture media at 2-8ºC.



1. Suspend 59.5gm of the dehydrated culture media in 1 liter of distilled or deionized water. Stir to mix thoroughly.

2. Heat to boiling to dissolve completely.

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

4. Cool to 45-50ºC.

5. Aseptically add 10ml of sterilized solution containing 4.0mg of cefsulodin and 2.5mg of novobiocin.


For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. G20.


Citrobacter species, Enterobacter agglomerans, Serratia liquefaciens, Y. frederiksenii, Y. intermedia, and Y. kristensenii may grow on CIN Agar and resemble Y. enterocolitica ("bull's-eye" colony morphology), but are easily differentiated by biochemical tests.

Enterobacter cloacae and Serratia marcescens are not inhibited on CIN Agar. However, they usually appear as raised, mucoid colonies with diffuse, pink coloration.

Characteristic pigmentation is stronger and more complete at 25ºC. and 48 hours of incubation than at 35ºC. for 24 hours of incubation. It has been found that some Yersinia strains may be inhibited at 35ºC. The lower temperature is recommended for primary isolation.


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


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Yersinia enterocolitica
ATCC ® 9610
A 24-48hr 25°C Aerobic Growth; red center, transparent border
Aeromonas hydrophila
ATCC ® 7966
A 24-48hr 35°C Aerobic Growth; red center, transparent border
Proteus mirabilis
ATCC ® 12453
B 24-48hr 35°C Aerobic Partial to complete inhibition
Enterococcus faecalis
ATCC ® 29212
B 24-48hr 35°C Aerobic Partial to complete inhibition
Pseudomonas aeruginosa
ATCC ® 27853
B 24-48hr 35°C Aerobic Partial to complete inhibition
Escherichia coli
ATCC ® 25922
B 24-48hr 35°C Aerobic Partial to complete inhibition

User Quality Control

Physical Appearance

CRITERION™ Yersinia Selective Agar (CIN) Base powder should appear homogeneous, free-flowing, and light pinkish-beige in color. The prepared media should appear clear, slightly opalescent, and reddish-purple 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. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

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

6. Schiemann, D.A. 1979. Synthesis of a selective agar medium for Yersinia enterocolitica. J. Microbiol.; 25:1298.

7. Schiemann, D.A. 1982. Development of a two-step enrichment procedure for recovery of Yersinia enterocolitica from food. Appl. Environ. Microbiol.; 43:14.

8. Altorfer, Regine, et al. 1985. Journal of Clinical Microbiology, Vol. 22, No. 4, p.478-480. American Society of Microbiology.

ATCC is a registered trademark of the American Type Culture Collection.
Irgasan is a registered trademark of Geigy Chemical Corp.