Tryptone Soya Broth w/ Phenol red

Intended Use

Tryptone Soya Broth with Phenol Red is a general purpose medium used for cultivation of a wide variety of microorganisms and recommended for sterility testing of moulds and lower bacteria.

Composition**

Final pH ( at 25°C) 7.3±0.2

**Formula adjusted, standardized to suit performance parameters

Directions

Suspend 30.02 grams in 1000 ml distilled water. Heat if necessary to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.

Principle And Interpretation

Tryptone Soya Broth with Phenol Red is modification of Tryptone Soya Broth (1, 2) with added pH indicator, phenol red. This facilitates identification of growth due to utilization of sugar indicated by colour change and turbidity. This medium therefore can be used for cultivation as well as for sterility testing.

The combination of pancreatic digest of casein and papaic digest of soyabean meal makes this medium nutritious by providing amino acids and long chain peptides and growth factor for the growth of microorganisms. Dextrose is carbohydrate source, which will be utilized by growing micro-organism resulting change in pH. which is indicated by colour change of the medium from red to yellow due to pH indicator, phenol red. Dipotassium phosphate buffers the medium. Sodium chloride maintains the osmotic balance of the medium.

Quality Control

Appearance Light yellow to pink homogeneous free flowing powder

Colour and Clarity of prepared medium Light pink coloured clear solution without any precipitate.

Reaction Reaction of 3.0% w/v aqueous solution at 25°C. pH : 7.3±0.2

pH 7.10-7.50

Cultural Response M1664: Cultural characteristics observed after an incubation at 35 - 37°C for 18 - 48 hours.

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.

Reference

1. The United States Pharmacopoeia / National Formulary, 1995, 23/18, The United States Pharmacopeial Convention Inc., Rockville, MD.
2. Indian Pharmacopeia, 1996, Govt. of India, Ministry of Health and Family Welfare, New Delhi, India.