ONPG Broth

[所属分类:培养基配方] [发布时间:2021-6-28] [发布人:网站管理员2] [阅读次数:] [返回]

ONPG Broth

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 water.........................................................................750.0mL
ONPG solution.......................................................................250.0mL
pH 7.2–7.4 at 25°C
ONPG Solution:
Composition per 250.0mL:
ONPG (o-nitrophenyl-β- D- galactopyranoside).............................1.5g
Sodium phosphate buffer (0.01M, pH 7.5)............................250.0mL
Preparation of ONPG Solution: Add ONPG to 250.0mL of sodi-
um phosphate buffer. Mix thoroughly. Filter sterilize.
Peptone Water:
Composition per 750.0mL:
Peptone .........................................................................................7.5g
NaCl............................................................................................3.75g
Preparation of Peptone Water: Add components to distilled/de-
ionized water and bring volume to 750.0mL. Mix thoroughly. Gently
heat and bring to boiling. Adjust pH to 8.0–8.4. Continue boiling for
10 min. Filter through Whatman #1 filter paper. Readjust pH of filtrate
to 7.2–7.4. Autoclave for 20 min at 10 psi pressure–115°C. Cool to
25°C.
Preparation of Medium: Aseptically combine the sterile ONPG
solution with the cooled, sterile peptone water. Mix thoroughly. Asep-
tically distribute into tubes in 2.5–3.0mL volumes. Store at 4°C for up
to 1 month.
Use: For the differentiation of a variety of Gram-negative bacteria
based on production of β-galactosidase. For the differentiation of lac-
tose-delayed bacteria from lactose-negative bacteria. For the differen-
tiation of Pseudomonas cepacia (positive) and Pseudomonas malto-
phila (positive) from other Pseudomonas species (negative). Bacteria
that produce β-galactosidase turn the medium yellow.