Cat. no. C6990 CRITERION™ Staphylococcus Medium 110 298gm
Cat. no. C6991 CRITERION™ Staphylococcus Medium 110 500gm
Cat. no. C6992 CRITERION™ Staphylococcus Medium 110 2kg
Cat. no. C6993 CRITERION™ Staphylococcus Medium 110 10kg
Cat. no. C6994 CRITERION™ Staphylococcus Medium 110 50kg


Hardy Diagnostics CRITERION™ Staphylococcus Medium 110 is used for isolating and differentiating staphylococci based on fermentation, pigment formation and gelatinase activity.

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.


Staphylococcus Medium 110 is commonly referred to as Staphylococcus Agar No. 110 and/or Stone Gelatine Agar. Staphylococcus Agar No. 110 was developed by Chapman for the primary isolation of staphylococci.(1) The high salt concentration contributes to the selective isolation of pathogenic staphylococci. On this medium, pathogenic strains of staphylococci usually produce yellow to orange pigmented colonies. Orange pigmented colonies are picked and inoculated into Brain Heart Infusion or Tryptose Phosphate Broth for the coagulase test. Mannitol-fermentation is indicated by a color change of bromcresol purple after placing a drop of the dye onto the areas of the agar surface from which the colonies have been removed. Gelatin hydrolysis is determined by flooding the plate with 5ml of a saturated aqueous solution of ammonium sulfate and incubating plate at 35 degrees C. for 10 minutes. A clear zone around the colonies indicates gelatin hydrolysis.


Gram weight per liter: 149.0gm/L
Sodium Chloride 75.0gm
Gelatin 30.0gm
Pancreatic Digest of Casein 10.0gm
Mannitol 10.0gm
Dipotassium Phosphate 5.0gm
Yeast Extract 2.5gm
Lactose 2.0gm
Agar 15.0gm

Final pH 7.0 +/- 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 2-8ºC.



1. Suspend 149.0gm of the dehydrated culture media in 1 liter of distilled or deionized water.

2. Heat to boiling and mix to dissolve completely.

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

4. Cool to 45-50ºC.

5. With gentle agitation to avoid bubbles thoroughly mix medium prior to pouring into sterile plates.

Note: Alternately, the medium may be prepared without sterilization. Boil the medium for five minutes and mix accordingly. However, this method of preparation requires that plates be used the same day they are prepared.


For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. G52.


Enterococcus faecalis may grow on Staphylococcus Medium 110 as tiny colonies with mannitol fermentation. Differentiate these organisms from staphylococci with the gram stain and catalase test.

Suspected staphylococci must be subcultured to Nutrient Broth, Blood Agar, BHI Broth, or Tryptose Phosphate Broth for coagulase testing as the high salt content of Staphylococcus Medium 110 may interfere with results.

Pigment production is not a reliable criterion for differentiation of Staphylococcus spp.


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


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Staphylococcus aureus
ATCC ® 25923
A 24-48hr 35°C Aerobic Growth; mannitol positive/gelatin positive. Pigment is seen as yellow to orange color
Staphylococcus epidermidis
ATCC ® 12228
A 24-48hr 35°C Aerobic Growth; mannitol negative/gelatin positive
Escherichia coli
ATCC ® 25922
B 24-48hr 35°C Aerobic Partial to complete inhibition

User Quality Control


CRITERION™ Staphylococcus Medium 110 powder should appear homogeneous, free-flowing, and light beige in color. The prepared media should appear opalescent with a moderate precipitate, and light amber in color.


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

2. FDA. 1995. Bacteriological Analytical Manual, 8th ed. FDA.

3. Stone, R.V. 1935. A cultural method for classifying staphylococci as of the "food poisoning" type. Proc. Soc. Exptl. Biol. Med., 33:185-187.

4. Chapman, G.H., et al. 1937. Isolation and cultural differentiation of food-poisoning staphylococci. Food Research; 2:349.

5. Chapman, G.H. 1945. The significance of sodium chloride in studies of staphylococci. J. Bacteriol.; 50:201.

6. Chapman, G.H. 1946. A single culture medium for selective isolation of plasma-coagulating staphylococci and for improved testing of chromogenesis, plasma coagulation, mannitol fermentation and the Stone reaction. J. Bacteriol.; 51:409.

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