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产品名称:葡萄糖胰蛋白胨琼脂|Dextrose Tryptone Agar
供应商:Oxoid
货号:CM0075
规格:500g
产品说明：
Directions
Suspend 27g in 1 litre of distilled water and bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes.
Technique
The instructions given below are included only as an indication of the mode of use of Dextrose Tryptone Agar, and will vary according to the original sample and the exact purpose of the investigation. For more exact details of technique it is advisable to consult one of the standard manuals mentioned in the references.
Enumeration of Mesophiles - into each of 5 Petri dishes, pipette dilutions of the sample to be tested. Cover and mix the inoculum with sterile Dextrose Tryptone Agar and incubate for 72 hours at 32°C. Count the total number of colonies, with separate totals for acid producing (yellow halo) and non-acid producing colonies.
Enumeration of `flat-sour’ Thermophiles - inoculate as above and incubate for 48 hours at 55°C. `Flat-sour’ colonies (e.g. Bacillus stearothermophilus) are typically round, 2-5mm in diameter, with an opaque centre, and surrounded by a yellow zone in contrast with the purple medium.
Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared agar plates at 2-8°C.
Appearance
Dehydrated Medium: Mauve coloured, free-flowing powder.
Prepared medium: Purple coloured gel |