Vogel and Johnson Agar

Cat. no. G193 Vogel and Johnson Agar, 15x100mm Plate, 19ml 10 plates/bag
Cat. no. J314 Cetrimide Selective Agar / MacConkey Agar / Vogel and Johnson Agar, 15x100mm Triplate, 7ml/section 10 plates/bag


Hardy Diagnostics Vogel and Johnson Agar is a selective medium used for the detection of coagulase-positive, mannitol-positive Staphylococcus aureus strains in clinical specimens and foods.


Vogel and Johnson Agar was developed by Vogel and Johnson as a modification of the Tellurite Glycine Agar medium described by Zebovitz, Evans, and Niven. (7,8) Vogel and Johnson increased the mannitol content of the Tellurite Glycine Agar and added a pH indicator, phenol red. The pH indicator enables the detection of mannitol fermentation, a differentiating characteristic of most strains of Staphylococcus aureus . Coagulase-positive strains of S. aureus form characteristic black colonies on the medium due to the reduction of tellurite. Colonies of mannitol-fermenting strains will be surrounded by a yellow zone. The Association of Analytical Chemists (AOAC) has recommended the medium for detection of S. aureus in foods. (5)

Due to the high selectivity and sensitivity of the medium, Vogel and Johnson Agar may be used for the rapid detection of S. aureus in clinical specimens when detection of the etiologic agent is of singular importance. Other microorganisms are easily distinguished by their inability to produce black colonies. Selective agents incorporated into the medium are glycine and lithium chloride, which inhibit the growth of most other microorganisms. Potassium tellurite is an inhibitory agent and is easily reduced by coagulase-positive staphylococci, leaving a black precipitate in the colony.


Ingredients per liter of deionized water:*

Pancreatic Digest of Casein 10.0gm
Glycine 10.0gm
Mannitol 10.0gm
Yeast Extract 5.0gm
Dipotassium Phosphate 5.0gm
Lithium Chloride 5.0gm
Phenol Red 25.0mg
Agar 15.0gm

Final pH 7.2 +/- 0.2 at 25ºC.

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


Storage: Upon receipt store at 2-8ºC. away from direct light. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.



Specimen Collection: Consult listed references for information on specimen collection. (2-6) Infectious material should be submitted directly to the laboratory without delay and protected from excessive heat and cold. If there is to be a delay in processing, the specimen should be inoculated into an appropriate transport medium and refrigerated until inoculation.

1. Inoculate and streak the specimen as soon as possible upon receipt in the laboratory.

2. If material is being cultured directly from a swab, roll the swab over a small area of the agar surface and streak for isolation. The selective qualities of this medium are such that the inoculum may be heavily applied.

3. Incubate plates aerobically at 35-37ºC. for 24-48 hours.

4. After 24 hours incubation, examine plated for characteristic black colonies which may or may not be surrounded by a yellow zone.

5. After 48 hours incubation, other organisms may exhibit slight growth. All black colonies should be Gram stained and a coagulase test performed for culture confirmation.


Staphylococcus aureus will produce black colonies with a yellow zone surrounding growth. Other staphylococci will also grow well and exhibit gray-black colonies without a yellow zone.


If tellurite is reduced but mannitol is not fermented, the medium surrounding colonies may be a deeper red color. This occurs due to the utilization of proteins in the medium and results in an increase in alkalinity. (3)


Standard microbiological supplies and equipment such as loops, swabs, applicator sticks, other culture media, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Staphylococcus aureus
ATCC ® 25923**
A 18-48hr 35°C Aerobic Growth; black colonies with yellow zones
Staphylococcus epidermidis
ATCC ® 12228
B 18-48hr 35°C Aerobic Growth, poor; gray-black colonies
Escherichia coli
ATCC ® 25922**
B 18-48hr 35°C Aerobic Partial to complete inhibition
Enterococcus faecalis
ATCC ® 29212
B 18-48hr 35°C Aerobic Partial to complete inhibition

** Recommended QC strains for User Quality Control according to the CLSI document M22 when applicable.


Physical Appearance

Vogel and Johnson Agar should appear slightly opalescent, and reddish-orange 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. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Medical Bacteria , Vol. I. Williams & Wilkins, Baltimore, MD.

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

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

6. U.S. Food and Drug Administration. Bacteriological Analytical Manual. AOAC, Arlington, VA. www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006949.htm

7. Vogel, R.A. and M.J. Johnson. 1960. Public Health Lab ; 18:131.

8. Zebovitz, E., et al. 1955. J. Bacteriol. ; 70:686.

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