SD-39 Agar is used in the presumptive enumeration of Escherichia coli O157:H7, and used with ISO-GRID® and/or NEO-GRID® Membrane Filtration System. SD-39 Agar conforms to AOAC Method #997 for food commodities in a laboratory setting. SD-39 Agar is not intended for use in the diagnosis of disease or other conditions in humans.

SD-39 Agar was formulated for direct presumptive enumeration of Escherichia coli O157:H7, and its direct differentiation from most other E. coli. SD-39 Agar combines some features of Lactose Monensin Glucuronate Agar and EF-18 Agar. Formula modifications include the addition of a chromogenic substrate for detection of β-glucuronidase activity and substitution of sorbitol for lactose or sucrose as a fermentable carbohydrate. The formula also enables direct differential enumeration of β-glucuronidase-positive E. coli.

SD-39 Agar is recommended for the direct, presumptive enumeration of E. coli O157:H7 in meats, poultry, dairy foods, infant formula, liquid eggs, mayonnaise, and apple cider. This medium is also used for the direct enumeration of β-glucuronidase-positive E. coli from foods.


Formula Litre
Enzymatic Digest of Animal Tissue 5 g
Yeast Extract 3 g
Sodium Chloride 5 g
L-Lysine 10 g
Dextrose 2.5 g
Sorbitol 20 g
Magnesium Sulfate 1.5 g
Monensin 0.038 g
Sodium Deoxycholate 0.15 g
Sodium Glucuronate 0.5 g
Novobiocin 0.0075 g
Phenol Red 0.12 g
X-Gluc 0.05 g
Agar 15 g

Final pH: 7.2 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Suspend 63 g of the medium in one litre of purified water.
  2. Heat with frequent agitation to boiling to completely dissolve the medium.

Order Details

Product # Product Description
6907A SD-39 Agar, 500 g

Reference Material

6907 - SD-39 Agar, Material Safety Data Sheet [English]
6907 - SD-39 Agar, Product Information Sheet [English]

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