BACILLUS CEREUS Med Bacillus Cereus Agar-(CM617-Oxoid B.C. Supplement-(SR99-Oxoid) Egg Yolk Emulsion-(SR47-Oxoid) Media Preparation Dissolve 205gm of agar in 475ml distilled water by bringing to the boil Sterilize at 121C for 15 minutes. Cool to 50C and asceptically add the contents of 1 vial of B Cereus supplement which has been rehydrated with 2mls of sterile distilled water and 25ml of Egg Yolk Emulsion. Mix well and pour 100mls onto sterile petri dishes. Store plates at 4'C. Method Pipette 0. Iml of 10% homogenate onto a prepared place and spread using a sterile spreader Incubate at 37C for 24 hours. Examine plates for peacock blue colonies surrounded by egg precipitate of the same colour. Leave for a further 24 hours at room temperature(16C)for all colonies to develop. Count colonies and multiply by 100 to give count per gm STAPHYLOCOCCUS AUREUS Baird-Parker Medium( CM275-Oxoid) Egg Yolk-Tellurite Emulsion(SR54-Oxoid) Media Preparation Dissolve 63gm of Baird-Parker medium in 1 litre of distilled water, sterilize for 15 minutes at 121C. Allow to cool to 50C and asceptically add 50ml of Egg tellurite emulsion, mix well. Pour approximately 1.mls onto sterilized petri dishes and allow to set, store prepared plates at 4.C Method Pipette 0.1 ml of the 10% homogenate onto a prepared plate and spread over the surface using a glass spreader Incubate upside down at 37'C for 24 hours Count black shiny convex 1.0-10.5mm diameters st. Aureus colonies multiply by 100 to give number per gm If no colonies appear incubate for a further 24 hoursBACILLUS CEREUS Media Bacillus Cereus Agar-(CM617 - Oxoid) B.C. Supplement-(SR99 - Oxoid) Egg Yolk Emulsion-(SR47 - Oxoid) Media Preparation Dissolve 20.5gm of agar in 475m1 distilled water by bringing to the boil. Sterilize at 121°C for 15 minutes. Cool to 50°C and asceptically add the contents of 1 vial of B. Cereus supplement which has been rehydrated with 2mls of sterile distilled water and 25ml of Egg Yolk Emulsion. Mix well and pour 100mls onto sterile petri dishes. Store plates at 4". Method Pipette O.lml of 10% homogenate onto a prepared place and spread using a sterile spreader. Incubate at 37°C for 24 hours. Examine plates for peacock blue colonies surrounded by egg precipitate of the same colour. Leave for a further 24 hours at room temperature (16°C) for all colonies to develop. Count colonies and multiply by 100 to give count per gm. STAPHYLOCOCCUS AUREUS Media Baird-Parker Medium (CM275 - Oxoid) Egg Yolk-Tellurite Emulsion (SR54 - Oxoid) Media Preparation Dissolve 63gm of Baird-Parker medium in 1 litre of distilled water, sterilize for 15 minutes at 121°C. Allow to cool to 50°C and asceptically add 50ml of Egg￾tellurite emulsion, mix well. Pour approximately l.Omls onto sterilized petri dishes and allow to set, store prepared plates at 4°C. Method Pipette 0.1 ml of the 10% homogenate onto a prepared plate and spread over the surface using a glass spreader. Incubate upside down at 37°C for 24 hours. Count black shiny convex 1.0-10.5mm diameters st. Aureus colonies, If no colonies appear incubate for a further 24 hours. multiply by 100 to give number per gm. 249