TITAN MEDIA ACETATE DIFFERENTIAL AGAR TM 006 For the differentiation of Shigella species from members of the genus Escherichia coli Composition Ingredients
Gms/Ltr.
Agar
20
Sodium chloride
5.00
Sodium acetate
2.00
Ammonium phosphate ( Mono)
1.00
Dipotassium phosphate
1.00
Magnesium sulphate
0.10
Bromothymol blue
0.08
* Dehydrated powder, hygroscopic in nature, store in a dry place, in tightly-sealed containers below 25°C and protect from direct Sunlight. Instructions for Use Dissolve 29.18gms in 1000ml distilled water. Gently heat to boiling with gentle swirling and dissolve the medium completely. Sterilize by autoclaving at 15 psi (121°C) for 15 minutes. Allow to cool the medium in slanted positions for use. Appearance: Emerald colour, clear to slightly opalescent gel pH (at 250C): 6.7 ± 0.2 Principle ACETATE DIFFERENTIAL AGAR is used for the differentiation of Shigella species from members of the genus Escherichia coli. The medium consists of a mixture of salts and Sodium acetate, as a sole source of carbon. Typical cultures of Shigella sp. are unable to utilize acetate and fail to grow; therefore, the medium remains unchanged. The majority of E. coli organisms grow well within 24-48 hours, but some strains grow more slowly. The growth is indicative of the use of Acetate, which results in the production of alkaline products. The increment in pH creates a blue color in the medium due to the presence of Bromothymol blue. Interpretation Cultural characteristics observed after inoculating (103CFU/ml), on incubation at 35 ± 37°C for 7 days.
Microorganisms
ATCC
Inoculum (CFU/ml)
Growth
Escherichia coli
25922
10³
Luxuriant
Salmonella Typhi
19430
10³
Poor
Proteus vulgaris
13315
10³
None
References 1. Simmons, J.S. J.Infect. Dis.39209. (1926). 2. Trabulsi, L.R. and W.H. Ewing Public Health Lab.20.137. (1962). 3. Edwards, P.R. and W.H. Ewing. Identification of Enterobacteriaceae. (1972). For more details visit:- http://www.titanmedia.in/images/upload/td/TM%20006_ACETATE%20DIFFERENTIAL %20AGAR%20TM%20006.pdf or http://www.titanmedia.in