Jan 11, 2009
Introduction of New SRL Media
Water is one of the prime elements responsible for life on earth. Contaminated water may contain pathogens like few types of bacteria, viruses, protozoa and other organisms that can endanger health and life.
Large volumes of water samples are usually tested using Membrane Filter Technique. This technique gives highly reproducible and numerical results more rapidly, than the multiple Tube Procedure.
Apart from the currently available membrane filter media, SRL has also introduced two new membrane filter media.
AM031 ASPARAGINE PROLINE BROTH
Asparagine Proline Broth is used for the cultivation of Pseudomonas aeruginosa by membrane filter technique.
It contains DL-Asparagine-2.0 gm, L-Proline-1.0 gm, Dipotassium phosphate, anhydrous- 1.0 gm, Magnesium sulphate - 0.5 gm, Potassium sulphate – 10.0 gm, per liter.
The amino acids, DL-Asparagine and L-Proline are readily utilized by Pseudomonas for their growth. Phosphates and sulphates provide the ions for the growth as well as act as buffering agents to promote the growth of the organisms.
LM024 LACTOSE TTC AGAR
Lactose TTC Agar is a selective and differential medium used for the isolation and detection of Escherichia coli and coliform bacteria in water by the membrane filter technique.
It contains Lactose-20.0 gm, Peptone -10.0gm, Yeast extract-6.0 gm, Meat extract-5.0 gm, Tergitol- 0.1 gm, Bromothymol Blue-0.05 gm, Agar-15 gm, per liter.
Peptone and Meat extract provide the necessary growth factors. Yeast extract is the source of B vitamins, organic nitrogen and carbon. Lactose is degraded to produce acid that is indicated by the pH indicator Bromothymol Blue which changes the color of medium under membrane to yellow. Selectivity is obtained by the use of Sodium heptadecyl sulphate (Tergitol 7) and 2, 3, 5 - Triphenyl Tetrazolium Chloride. Lactose negative bacteria reduce TTC to insoluble formazan producing dark red colonies, while Lactose positive Escherichia coli reduces TTC weakly, hence producing yellow-orange colored colonies.