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TBX Agar (Tryptone Bile X-glucuronide Agar) (TBX Chromogen Medium)

[所属分类:培养基配方] [发布时间:2021-12-20] [发布人:网站管理员2] [阅读次数:] [返回]

TBX Agar

(Tryptone Bile X-glucuronide Agar)

(TBX Chromogen Medium)

山东拓普生物工程有限公司培养基配方 http://www.topbiol.com

Composition per liter:

Peptone .............................................................20.0g

Agar ..................................................................15.0g

Bile salts..............................................................1.5g

X-β-D-glucuronide..........................................0.075g

pH 7.2 ± 0.2 at 25°C

Source: This medium is available from Fluka, Sig

ma-Aldrich and Oxoid.

Preparation of Medium: Add components to

distilled/deionized water and bring volume to 1.0L.

Mix thoroughly. Gently heat while stirring and bring

to boiling. Autoclave for 15 min at 15 psi pressure–

121°C. Pour into sterile Petri dishes.

Use: For the detection and enumeration of E. coli in

foodstuffs, animal food and water without further

confirmation. E. coli colonies are colored blue-green.

Unlike MUG, where the flurophore leaches out of the

cell into the surrounding agar, the released chro

mophore in TBX Medium is insoluble and accumu

lates within the cell. This ensures that colored target

colonies are easy to identify. Most E. coli strains can

be differentiated from other coliforms by the pres

ence of the enzyme glucuronidase. The chromogen in

TBX Medium is 5-bromo-4-chloro-3-indolyl-β-D

glucuronide (X-glucuronide), and is targeted by this

enzyme. E. coli cells are able to absorb this complex

intact and intracellular glucuronidase splits the bond

between the chromophore and the glucuronide. The

released chromophore is colored and builds up with

in the cells, causing E. coli colonies to be colored

blue/green.