Aeromonas Differential Agar (Dextrin Fuchsin Sulfite Agar)

[所属分类:培养基配方] [发布时间:2019-9-23] [发布人:] [阅读次数:] [返回]

山东拓普生物工程有限公司

Shandong Tuopu Biol-Engineering Co.,Ltd

Aeromonas Differential Agar
(Dextrin Fuchsin Sulfite Agar)
Composition per liter:
Dextrin........................................................................................15.0g
Agar ............................................................................................13.0g
Pancreatic digest of casein..........................................................10.0g
Na 2 HPO 4 .....................................................................................7.75g
NaCl..............................................................................................5.0g
Beef extract...................................................................................3.0g
Na 2 SO 3 ..........................................................................................1.6g
Acid Fuchsin solution..............................................................50.0mL
pH 7.5 ± 0.2 at 25°C
Acid Fuchsin Solution:
Composition per 50.0mL:
Acid Fuchsin...............................................................................0.25g
Aqueous dioxan, 5%................................................................50.0mL
Preparation of Acid Fuchsin Solution: Add Acid Fuchsin to
50.0mL of 5% aqueous dioxan. Mix well to dissolve.
Caution: Acid Fuchsin is a potential carcinogen and care must be tak-
en to avoid inhalation of the powdered dye and contamination of the
skin.
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. Distribute into tubes or flasks. Autoclave
for 15 min at 15 psi pressure–121°C. Pour into sterile Petri dishes or
leave in tubes.
Use: For the isolation and differentiation of Aeromonas species from
other Gram-negative rods such as Pseudomonas and Enterobacteri-
aceae. Specimens with low numbers of Aeromonas may first be
enriched by growth in starch broth for 4–9 days. After 24 hrs of growth
on this agar, colonies are sprayed with Nadi reagent (1% solution of
N,N,N′,N′-tetramethyl-p-phenylene-diammonium dichloride). A posi-
tive Nadi reaction (dextrin degradation) is indicated by a purple color
at the periphery of the colony. Dextrin fermentation is also indicated by
red colonies. Aeromonas species appear as large, convex, dark red col-
onies with a purple periphery.