Make your own free website on

Biochemical Test

Biochemical Test

Biochemical Test
Agar Plates
Coagulase Test
The Catalase Test
Indole Test
Oxidase Test
Citrate Test
Optichin Test
Urease test

Selective medium & Differential medium


A selective medium is one that allows the proliferation of some organisms while repressing the thriving of others. Selection is done through (1) regulation of medium composition, (2)modification of atmospheric or (3) alteration of incubation temperature. A differential medium, however, does not inhibit the proliferation of organisms and will cause some colonies to grow unusually from other existing organisms. Current media includes both selective and differential ingredients. One example of such preparation is Bacto-Brilliant Green gar, which happens to be a highly precise preparation used for the separation of Salmonella species other than S. Typhi, the agent (responsible for the onset of Typhoid Fever) is commonly found in feces or other specimens thought to encompass these organisms. The brilliant green dye represses the proliferation of other bacteria. In its composition, lactose and sucrose acts as the main source for enzymatic action. On normalcy, Salmonella appears as pink-white opaque colonies ringed with brilliant red zones. Easily differentiated, organisms that have same capacity as Salmonella to proliferate on the medium are demarcated by appearance of yellow-green colonies ringed with intense yellow-green areas.

Test of patient's blood with biochemical to test for diseases.

The main purpose of conducting biochemical tests is to identify microorganisms and then, group them under different species and family under the term Microbiology. There are hundred and millions of species we believed are not yet identified. Therefore, it is  a need to classify and identify them into group, type, family, etc. By classifying the organismsm, it will be much easier for microbiologists to conduct experiments which can lead to more discoveries. Besides that classification and identification, can help in medical uses like identifying the cause of a disease, and it can also help in the field of drug development. In drug developments test, biochemical tests is an essential and crucial process. Under pre-clinical and clinical trials, the specimens of the animal is examined after it has consumed the test drug. Follow by a series of testing with biochemicals to determine if the drug is working or does it causes any side effects.