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产品名称:亚硫酸铁琼脂 Iron Sulphite Agar
供应商:Oxoid
货号:CM0079
规格:500g
产品说明：
Directions
Suspend 23.0g in 1 litre of distilled water and boil to dissolve completely. Sterilise by autoclaving for 15 minutes at 121°C. Mix well before pouring.
Appearance
Dehydrated medium: Light straw coloured, free-flowing powder
Prepared medium: Straw-grey coloured gel
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 medium below 25°C.
Technique
Iron Sulphite Agar is particularly suitable for the detection of thermophilic anaerobic organisms causing sulphide spoilage in food. The medium should be dispensed in 10ml amounts in tubes for deepshake cultures, and inoculated whilst fluid at about 50°C. Allow to set and incubate at 55°C for thermophilic species. Desulfotomaculum nigrificans, the type species, produces distinct black spherical growths in the depth of the medium.
In the Attenborough and Scarr method 4, diluted samples of the sugar were filtered through membrane filters which were then rolled up and placed in tubes containing enough melted Iron Sulphite Agar (at approximately 50°C) to cover them. The medium was allowed to solidify and the tubes were incubated at 56°C. After 48 hours the number of black colonies on the membrane was counted. This membrane filter technique is quicker than the standard method but of comparable accuracy, and permits the examination of a much larger sample 5. |