Prepared Plated Media PPM

MACCONKEY AGAR

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Catalog Number : 900

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Description

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MACCONKEY AGAR is used for the selective isolation and identifi cation of Enterobacteriaceae from feces, urine, wastewater and foods. It is also a selective and diff erential medium for the isolation of enteric Gram-negative bacteria.The specimen can be streaked directly on the medium or inoculated fi rst into an enrichment broth such a Tetrathionate Broth (Cat. 1114), Selenite Cystine Broth (Cat. 1220), GN Enrichment Broth (Cat. 1248) or MacConkey Broth (Cat. 1210).Subculture the broth tubes on MacConkey Agar and incubate at 30 - 35°C for 18 - 72 hours, as indicated by the European Pharmacopoeia.Pancreatic Digest of Gelatin and Peptones (Meat & Casein) provide nitrogen, vitamins, minerals and amino acids essential for growth. Lactose is the fermentable carbohydrate providing carbon and energy. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bile salts and crystal violet are the selective agents, and inhibit Gram-positive organisms. Neutral red is the pH indicator. When lactose is fermented, the pH of the medium decreases, changing the color of neutral red to pink. Bacteriological agar is the solidifying agent.The European Pharmacopoeia in the Paragraph 2.6.13 “Microbiological examination of non-Sterile products: test for specifi ed microorganisms”, recommends to inoculate and incubate in casein soya been digest broth TSB Broth (Cat. 1224), at 30 - 35°C for 18 - 24 hours, to subculture in MacConkey Broth (Cat. 1210) and incubate at 42 - 44 °C for 24 - 48 hours after subculturing on a plate of MacConkey Agar at 30 - 35 °C for 18 - 72 hours.