Less selective than Macconkey Agar and will permit growth of Enterococci and Staphylococci. MacConkey Agar without Crystal Violet is a modified version of the first media developed for the isolation of Gram negative enteric bacteria. The deletion of crystal violet allows the growth of enterococci, staphylococci and Mycobacterium sp. Gram negative enteric bacteria which ferment lactose will produce red to pink colonies. Because this medium is less inhibitory medium it is recommended that specimens be plated on other more inhibitory Gram negative media such as Deoxycholate Agar.
Microorganisms
Enterococcus faecalis ATCC 29212: Pink colonies Escherichia coli ATCC 25922: Pink colonies Proteus mirabilis ATCC 12453: Colorless colonies Salmonella typhimurium ATCC 14028: Colorless colonies Staphylococcus aureus ATCC 25923: Pink colonies
Appearance
Supplied as a light pinkish-beige, free-flowing homogeneous powder
Solubility
Red-orange, trace to slightly hazy
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.
Directions per Liter
Mix 52 grams of the medium in one Liter of purified water until evenly dispersed. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121.0°C for 15 minutes.
Storage and Stability
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 4°C and used within a short period of time.
Formulation in grams per liter
Pancreatic Digest of Gelatin | 17.0 |
Agar | 12 |
Lactose | 10.0 |
Sodium Chloride | 5.0 |
Bile Salts Mixture | 5.0 |
Casein Digest Peptone | 1.5 |
Peptic Digest of Animal Tissue | 1.5 |
Neutral Red | 0.05 |
Crystal Violet | Absent |