Tryptone Lactose Iron HiVeg™ Agar

Composition**

Ingredients	Gms / Litre
HiVeg hydrolysate	20.000
Lactose	10.000
Ferrous sulphate	0.200
Sodium sulphite	0.400
Sodium thiosulphate	0.080
Phenol red	0.020
Agar	3.500
Final pH (at 25°C)	7.3±0.2

**Formula adjusted, standardized to suit performance parameters

Directions

Suspend 34.2 grams in 1000 ml distilled water. Heat boiling to dissolve the medium completely. Dispense in test tubes. Sterilize by autoclaving at 118°C for 15 minutes. Cool the tubes in an upright position.

Principle And Interpretation

Tryptone Agar was developed by Vera (1) for the accurate differentiation and identification of aerobes and anaerobes by means of motility and fermentation reactions. Tryptone Lactose Iron HiVeg Agar is a slight modification of Tryptone Lactose Iron Agar medium which is recommended to study motility of organism and simultaneous sulphite reduction in acidic environment.

Due to presence of phenol red in the medium, on fermentation of lactose the medium turns yellow due to production of acid and gas (2). The ability of an organism to produce H2S is a consistent characteristics and an H2S producer usually produce gas (CO2 + H2) in carbohydrate media (2) which is visualized as air bubbles in the medium.

The medium is prepared by completely replacing animal based peptones with veg peptones which are free from BSE/TSE risks.

HiVeg Hydrolysate provides essential growth nutrients to support the growth of organisms. Phenol red is the pH indicator. Even small amount of agar renders it suitable for study of motility. Small amounts of acid produced do not readily get dispersed throughout the medium and hence positive reaction can be more quickly determined in this medium than in liquid medium. Lactose is the fermentable carbohydrate.

H2S production takes place in the presence of R1-SH group provided by cystine present in HiVeg Hydrolysate or through reduction of an inorganic sulphur source such as thiosulphate. H2S is a colourless gas, which upon contact with ferrous salt produces ferrous sulphide, a black precipitate indicated by a visible black reaction (3-6). Sodium sulphite at a concentration less than 0.05% is not inhibitory to Clostridium sporogenes (7).

Quality Control

Appearance: Light yellow to pinkish purple homogeneous free flowing powder

Gelling: Semisolid, comparable with 0.35% Agar gel.

Colour and clarity of prepared medium: Red coloured clear to slightly opalescent gel forms in Petri plates

Reaction: Reaction of 3.4% w/v aqueous solution at 25°C. pH : 7.3±0.2

pH: 7.10-7.50

Cultural Response

MV321: Cultural characteristics observed when incubated anerobically after an incubation of 18 - 24 hours at 35 - 37°C.

Organism	Inoculum (CFU)	Growth	Acid	Gas	H2S	Motility
Clostridium perfringens ATCC 13124	50-100	luxuriant	Acid Production, + positive reaction, yellow colour	Positive reaction	Positive reaction, blackening of medium	Positive, growth away from stabline causing turbidity
Clostridium sporogenes ATCC 11437	50-100	luxuriant	Acid Production, + positive reaction, yellow colour	Positive reaction	Negative reaction, no blackening of medium	Positive, growth away from stabline causing turbidity

Storage and Shelf Life

Store below 30°C in tightly closed container and the prepared medium at 2-8°C. Use before expiry date on the label.

Product Information

More Information
Product Name	Tryptone Lactose Iron HiVeg™ Agar
SKU	MV321
Product Type	HiVeg™
Physical Form	Powder
Origin	Animal Free (Veg)
Packaging type	HDPE
References	1.Vera, 1944, J. Bacteriol., 47:455. 2.MacFaddin J. F., 1985, Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria, Vol. I, Williamsand Wilkins, Baltimore. 3.Clarke P. H. and Cowen S. T., 1952, J. Gen. Microbiol., 6:187. 4.Fieser L. F. ad Fieser M., 1956, Organic Chemistry, 3rd Ed., New York Reinhold Publishing Corporation. pg 155. 5.Doelle H. W., 1969, Bacterial Metabolism, New York, Academic Press, p. 99, 224. 6.Padron A. P. and Dockstader W. B., 1972, Appl. Microbiol., 23:1107. 7.Mossel D. A. A, et al, 1959, J. Path. Bacteriol., 78: 290.
Customized Product Available	No