Technical Data
Deoxycholate Lactose Agar (Powder)
Microbiological Grade
Storage RT/4C    Shipping RT
Components shown as g/liter
Peptic Digest of Animal Tissue5.0
Casein Digest Peptone 5.0
Sodium Chloride5.0
Sodium Citrate2.0
Sodium Deoxycholate0.5
Neutral Red0.033
Recovery of coliforms in milk and water.

Deoxycholate Lactose Agar was formulated by Leifson for the detection of coliforms in water, dairy products and other food materials. USBio recommends Violet Red Bile Agar as the medium of choice for isolating coliforms from food products. Growth of coliforms which ferment lactose produce red colonies surrounded by a zone of red precipitate. The fermentation of lactose produces acid products which lowers the pH of the medium and the neutral red dye in the medium turns bright red. Sodium citrate and sodium deoxycholate are added to inhibit the growth of Gram positive bacteria.

Store the sealed bottle containing the dehydrated medium at 2 to 30.0C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original light pinkish-beige color.

Directions: 1. Dissolve 42.5grams per liter of distilled/ deionized (DDI) water, heating with stirring until completely solubilized.

Do not autoclave. Storage:Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4C and used within a short period of time.

Microbiological Analysis: Escherichia coli ATCC 25922

Appearance: Light pinkish-beige, homogeneous, free flowing powder.

Solubility: Reddish-pink, clear, complete.

pH (25C): 7.10.2

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.