Bacterial Titer

Bacterial Titer

 

the maximum dilution of an aqueous suspension of bacteria in which the microorganisms can grow. To determine the bacterial titer, a certain amount of the material being examined, such as soil, water, or food, is placed in a test tube with sterile water and thoroughly mixed. Then 1 milliliter (ml) of the solution in the test tube is diluted tenfold in another test tube. Further dilutions are obtained by repeating the operation many times. By culturing samples of different dilutions in selective or differential diagnostic nutrient media intended for the growth of a given physiological group of bacteria, information may be obtained on the quantity of putrefactive, nitrifying, denitrifying, cellulose, and anaerobic bacteria in the material under study. In the testing of water and food for purposes of hygiene and sanitation, the coli index, or titer of colibacillus (Escherichia coli), is of great importance.

A. A. IMSHENETSKII

References in periodicals archive ?
At 0, 5, 10, 15, and 30 minutes, 3 samples of 60 ILl were collected, and the bacterial titer (number of cfu/ml) in these samples was determined by plating 10-fold dilutions on Columbia agar with 5% sheep blood.
Aliquots (100 [micro]L) of serial dilutions of logarithmically growing cultures were plated on trypticase soy agar to determine the bacterial titer.
Negative controls (sterile water, no template) and positive controls [PCs with low bacterial titers (30-50 x [10.