Product No.	Product Category	Specification
HCM159	Dehydrated Culture Medium	500g/bottle

Intended Use

For enumeration of Escherichia coli and coliforms in water, using membrane filter technique, replacing Membrane Enriched Teepol Broth.

Principle and Interpretation

Peptic digest of animal tissue and yeast extract provide carbon, nitrogen, amino acids, minerals, vitamins, trace elements and other essential nutrients for growth. Lactose is the fermentable sugar. Phenol red is the indicator and change from red to yellow because of the acid production from the fermentation. Sodium lauryl sulphate inhibits gram-positive organisms.

Formulation

Ingredients	/liter
Peptone（Peptic digest of animal tissue）	39.0g
Yeast extract	6.0g
Lactose	30.0g
Phenol red	0.2g
Sodium lauryl sulphate	1.0g
pH7.4±0.2 at 25°C

Preparation

Suspend 76.2g in 1 litre distilled water. Distribute into final containers, e.g. 100 ml screw cap bottles. Sterilise by steaming for 30 minutes on three consecutive days or by autoclaving at 121°C for 15 minutes.

Quality Control

Cultural characteristics after 24 hours at……

Quality control strains	Growth at 35°C	Growth at 44°C
Escherichia coli ATCC25922	+	+
Enterobacter aerogenes ATCC13048	+	–

Storage and Shelf Life

2-30℃，Keep container tightly closed, avoid direct sunlight.

Use before expiry date on the label.

 Precautions

1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort

2. Keep container tightly closed after using to prevent clumping.

Waste Disposal

Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.

Revision

On June 14, 2024

References

Environment Agency: The Microbiology of Drinking Water (2002). Methods for the Examination of Water and Associated Materials. Windle Taylor, E. (1961) Glutamic acid medium, 40th Ann Rep. Div. Water Exam. Met. Water Board London pp 18-22.