Tryptone Water (TW)

Tryptone Water (TW)
Indole Test Broth for Biochemical Identification of Enteric Bacteria

Catalog Number: AS-1367

Overview
Tryptone Water (TW) is a simple, nutrient-rich liquid culture medium used primarily for the detection of indole production and for the general cultivation of non-fastidious microorganisms. The medium contains tryptone as a source of amino acids and peptides, supporting microbial growth and enabling organisms that produce tryptophanase to convert tryptophan into indole.

Tryptone Water is widely used in clinical diagnostics, microbiological research, and food and water testing, particularly for biochemical identification of enteric bacteria.

Applications
• Detection of indole production from bacterial cultures
• General cultivation of non-fastidious microorganisms
• Biochemical testing and identification of enteric bacteria
• Research and educational applications in microbiology

Key Features & Benefits
• Simple, nutrient-rich formulation supporting growth of a wide range of bacteria
• Compatible with indole detection using Kovac’s reagent and similar reagents
• Non-selective medium suitable for non-fastidious organisms
• Versatile use in biochemical assays, routine microbiology, and teaching laboratories

Principle of the Medium
Tryptone Water provides peptides and amino acids derived from tryptone, allowing bacteria to grow and metabolize tryptophan. Organisms capable of producing tryptophanase convert tryptophan into indole, which can be detected by the addition of Kovac’s reagent, producing a characteristic pink to red colour. Growth in the medium indicates organism viability and metabolic activity.

Typical Composition (per litre)
Tryptone – 10.0 g
Sodium Chloride – 5.0 g
Purified Water – q.s. to 1 L

Final pH: 7.3 ± 0.2 at 25 °C

(Composition may be adjusted to meet specific institutional or published standards.)

Preparation
Suspend 15 g of dehydrated medium in 1 L of purified water.
Heat with gentle agitation until completely dissolved.
Dispense into tubes, flasks, or bottles as required.
Sterilize by autoclaving at 121 °C for 15 minutes.
Cool to room temperature before use.

Incubation & Interpretation
Incubate at 35–37 °C for 18–24 hours (up to 48 hours for slow-growing organisms).

Positive indole reaction: Pink or red colour after addition of Kovac’s reagent
Negative reaction: No colour change after reagent addition

Storage & Stability
Dehydrated medium: Store at 15–30 °C in a dry, tightly sealed container
Prepared medium: Store at 2–8 °C, protected from light
Shelf life: Use within the recommended period for optimal performance

Intended Use
For laboratory research and diagnostic use only.
Not for human, veterinary, food, feed, or pharmaceutical use.

Quality & Compliance
Manufactured under controlled conditions to ensure batch-to-batch consistency.
Suitable for clinical, food, water, and research microbiology.
Performance comparable to leading international microbiological media suppliers.

Customs & Trade Information
HS / AHECC Code: 3821.00.00
Prepared culture media for the development or maintenance of microorganisms