Cat. no. C5910 CRITERION™ Kligler Iron Agar (KIA) 104gm
Cat. no. C5911 CRITERION™ Kligler Iron Agar (KIA) 500gm
Cat. no. C5912 CRITERION™ Kligler Iron Agar (KIA) 2kg
Cat. no. C5913 CRITERION™ Kligler Iron Agar (KIA) 10kg
Cat. no. C5914 CRITERION™ Kligler Iron Agar (KIA) 50kg


Hardy Diagnostics CRITERION™ Kligler Iron Agar (KIA) is recommended for use in differentiating certain members of the Enterobacteriaceae by demonstrating hydrogen sulfide production and the fermentation of dextrose and lactose.

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.


CRITERION™ Kligler Iron Agar (KIA) combines features of Kligler's Lead Acetate medium and Russell's Double Sugar Agar.(8,9) Phenol red is added as the color indicator. The basal medium of KIA is composed of casein and meat peptones with the addition of lactose and dextrose. The production of acid by lactose- and/or dextrose-fermentation results in color changes of the phenol red pH indicator. Presence of the carbohydrates thus enables the differentiation of species of enteric bacilli.

Non-lactose-fermenters initially produce a yellow slant and butt as a result of dextrose fermentation. The concentration of dextrose is only one percent and, therefore, is rapidly exhausted. Once the dextrose is depleted, the reaction reverts to alkaline (red slant) due to the oxidation of acids. Reversion does not occur in the butt of the medium where an acidic environment (yellow butt) is maintained. Lactose-fermenting organisms produce yellow slants and butts. There is no reversion to red in the slant because enough acid is produced to maintain an acid pH under aerobic conditions. Non-fermenters produce red slants and butts. H2 S production results in a blackening of the medium, either throughout the butt or in a ring formation near the top of the butt. Gas production is demonstrated by the presence of bubbles or cracks in the medium.


Gram weight per liter: 52.0gm/L
Pancreatic Digest of Casein 10.0gm
Peptic Digest of Animal Tissue 10.0gm
Lactose 10.0gm
Sodium Chloride 5.0gm
Dextrose 1.0gm
Sodium Thiosulfate 0.5gm
Ferric Ammonium Citrate 0.5gm
Phenol Red 25.0mg
Agar 15.0gm

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 pinkish-beige.

Store the prepared culture medium at 2-8ºC.



1. Suspend 55.0gm of the dehydrated culture media in 1 liter of distilled or deionized water.

2. Heat to boiling and mix to dissolve completely.

3. Dispense into tubes.

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

5. Cool in slanted position with deep butts.


For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. L70.


It is important to stab the butt of the medium. Failure to stab the butt invalidates this test. The integrity of the agar must be maintained when stabbing. Caps must be loosened during this test or erroneous results will occur.

An organism that produces hydrogen sulfide may mask acid production in the butt of the medium. However, hydrogen sulfide production requires an acid environment, thus the butt portion should be considered acid if hydrogen sulfide is produced.

Certain species or strains may give delayed reactions or completely fail to ferment the carbohydrate in the stated manner. However, in most cases, if the organism fails to ferment dextrose within 48 hours and growth is definitely present, the organism is most likely not in the Enterobacteriaceae family.


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


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Salmonella enterica
ATCC ® 14028
C 18-24hr 35°C Aerobic Growth; red slant, yellow butt, black butt, H 2 S positive, gas positive
Escherichia coli
ATCC ® 25922
C 18-24hr 35°C Aerobic Growth; yellow slant, yellow butt, H 2 S negative, gas positive
Pseudomonas aeruginosa
ATCC ® 27853
C 18-24hr 35°C Aerobic Growth; red slant, red butt, H 2 S negative, gas negative

User Quality Control


CRITERION™ Kligler Iron Agar (KIA) powder should appear homogeneous, free-flowing, and pinkish-beige in color. The prepared media should appear slightly opalescent with a slight precipitate, and orange-red 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. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

3. Edwards, P.R., and M.A. Fife. 1961. Appl. Microbiol.; 9:478.

4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

5. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Bacteria, Vol. I. Williams & Wilkins, Baltimore, MD.

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

7. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22. Clinical and Laboratory Standards Institute (CLSI - formerly NCCLS), Wayne, PA.

8. J. Med. Res.; 25:217, 1911.

9. Am. J. Public Health; 7:1042, 1917.

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