HiCrome™ MS.O157 Agar with Tellurite (MS.O157 Agar with Tellurite, HiCrome™)

[所属分类:培养基配方] [发布时间:2021-4-8] [发布人: ] [阅读次数:] [返回]

HiCrome™ MS.O157 Agar with Tellurite

(MS.O157 Agar with Tellurite, HiCrome™)

培养基配方

Composition 1000.25mL:
Agar ............................................................................................12.0g
Peptone, special ..........................................................................10.0g
Sorbitol..........................................................................................4.0g
Bile salt mixture............................................................................1.0g
Chromogenic mixture...............................................................0.731g
Tellurite solution......................................................................0.25mL
pH 6.8 ± 0.2 at 25°C
Source: This medium is available as a premixed powder from HiMedia.
Tellurite Solution:
Composition per 10.0mL :
K 2 TeO 3 ..........................................................................................0.1g
Preparation of Tellurite Solution: Add K 2 TeO 3 to 10.0mL of distilled/deionized water. Mix thoroughly. Filter sterilize.
Caution: Potassium tellurite is toxic.
Preparation of Medium:  Add components, exept tellurite solution, to distilled/deionized water and bring volume to 1.0L. Mix thoroughly. Gently heat while stirring and bring to boiling. Do not autoclave. Cool to 45°C. Aseptically add 0.25mL sterile tellurite solution. Mix thoroughly. Pour into sterile Petri dishes.
Use: For the simultaneous detection of Escherichia coli, Escherichia coli O157:H7, and coliforms in water and food samples. Escherichia coli O157:H7 gives colorless colonies because of non-fermentation of sorbitol and absence of β-glucuronidase activity, whereas other strains of Escherichia coli having β-glucuronidase activity and fermenting sorbitol appear as steel blue colored colonies. Addition of tellurite makes the medium much more specific and selective.