Appearance (Colour)
Light yellow
Appearance (Form)
Free flowing, homogeneous powder
Solubility
63.10 gm/liter
Solubility before autoclaving (Clarity)
Clear to slightly opalescent
Gel strength (1.5% gel)
Firm, comparable with 1.5% agar gel
pH (25°C)
7.0 ± 0.2
Prepared Medium Appearance after autoclaving (Clarity)
Clear to slightly opalescent
Prepared Medium Appearance after autoclaving (Colour)
Light amber
Cultural Response
Inoculate and incubate at 35°C for 24-48 hours
Organism
Staphylococcus aureus ATCC 25923
Inoculum (cfu) 10-100
Growth : Good
Colony colour : Brown-black
Recovery Rate : 50.0%
Lecithinase activity : Positive Reaction(Halo or clear zone around colony)
Organism
Listeria monocytogenes ATCC 19112
Inoculum (cfu) 10-100
Growth : Good
Colony colour : Blue
Recovery Rate : 40.0%
Lecithinase activity : Negative
Organism
Micrococcus luteus ATCC 10240
Inoculum
Growth : None to Poor
Colony colour : Colourless
Recovery Rate : <=10.0%
Lecithinase activity : Negative
Organism
Staphylococcus epidermidis ATCC 12228
Inoculum
Growth : Poor
Colony colour : Yellow - Brownish
Recovery Rate : <=10.0%
Lecithinase activity : Negative
Organism
Escherichia coli ATCC 25922
Inoculum
Growth : None to Poor
Colony colour : Colourless
Recovery Rate : <=10.0%
Lecithinase activity : Negative
Organism
Bacillus subtilis ATCC 6633
Inoculum
Growth : None to Poor
Colony colour : Colourless
Recovery Rate : <=10.0%
Lecithinase activity : Negative
Applications
A chromogenic medium used for the identification of Staphylococcus aureus.
Principle
Casein enzymic hydrolysate, Pancreatic digest of gelatin, Beef extract (ex. buffalo) and Yeast extract provides nitrogenous requirements and other essential growth nutrients.
Sodium pyruvate protects injured cells and enhances in growth of Staphylococcus sps.
Lithium chloride and Potassium tellurite inhibits most of the contaminating microflora except Staphylococcus aureus. Addition of egg yolk yields in exhibition of proteolytic activity by producing clear zone around the colony.
Composition
Ingredients
gm/lt.
Casein enzymic hydrolysate
12.00
Pancreatic digest of gelatin
3.00
Beef extract (ex.buffalo)
6.00
Yeast extract
5.00
Sodium pyruvate
10.00
Lithium chloride
5.00
Chromogenic mixture
2.10
Agar
20.00
Directions
1. Add 63.10 gm powder to 950 ml of distilled/purified water and mix thoroughly.
2. Gently heat and bring to boiling.
3. Autoclave at 15 psi pressure at 121°C for 15 minutes.
4. Cool to 50°C and add aseptically 50ml Egg yolkTellurite emulsion.
