- Mac Conkey agar
- Isolation and diffential of Gram Negative Bacteria( Entero bacilli)
Composition
Grams/liter
Enzymatic digist
gelatin---------------------------------------------------------17.000
Enzymatic digist of
casein-----------------------------------------------------1.500
Enzymatic digist of Animal tissue (Protease
peptone)-------------------1.500
Lactose-----------------------------------------------------------------------------10.000
Bile salt
mixer--------------------------------------------------------------------1.500
Sodium
chloride------------------------------------------------------------------5.000
Neutral
red---------------------------------------------------------------------0.030
Crystal
yoilet----------------------------------------------------------------------0.001
Agar
-------------------------------------------------------------------------------13.5
- pH = 7.1± 0.2 at 250C
- Enzyamatic digist gelatin, Enzyamatic digisit of casein and Enzyamatic digist of Animal tissue(Proteose peptone) source of nitrogen and vitamins
- Lactose is fermentable carbohydrate
- Neutral red---------------ph indicator
- Bile salt mixer and Crystal yoilet ------------selective agents ----inhibiting gram positive cocci.
- Sodium chloride ----maintain the Osmatic Pressure
- Agar---------------solidifiying agent.
Appearance:
- Red colonies or Brick red colonies with bile precipitate.
- Some times surrounding by a reddish precipitation zone indicates pressure of coli forms.
- Shigella –colour less
- Salmonella –colour less
- Protius Vulgartus – colour less
- Mixture of sodium cholate and sodium deoxychollate.
- Water soluble.
- Is called gentian violet or methyl violet.
- Is a triary methane dye.
- Crystal violet has antibacterial, anti fungal, and topical antiseptic.
- Ball point pens, ink-jet printing.
- Gram stain method used this dye.
Neutral Red:
- Basic red Dye.
- Neutral red acts as a pH indicator,
- changing from red to yellow between the pH 6.8 – 8.0
Below 6.8 Above 8.0
