Biochemical tests are laboratory procedures that use specific chemical reactions to identify and characterize microorganisms, such as bacteria. These tests are often used to identify the presence of specific enzymes or metabolic pathways in a microorganism, which can help to distinguish it from other microorganisms.
Some common biochemical tests used in bacteriology include:
Oxidase test: This test is used to detect the presence of the enzyme cytochrome oxidase, which is involved in the metabolism of oxygen.
Catalase test: This test is used to detect the presence of the enzyme catalase, which helps to break down hydrogen peroxide.
Indole test: This test is used to detect the presence of the enzyme tryptophanase, which breaks down the amino acid tryptophan.
Nitrate reduction test: This test is used to detect the ability of a microorganism to reduce nitrate to nitrite.
Gelatinase test: This test is used to detect the ability of a microorganism to produce the enzyme gelatinase, which breaks down gelatin.
These are just a few examples of the many different biochemical tests that are used in bacteriology. Biochemical tests can be useful for identifying and classifying bacteria, and for understanding their metabolism and ecological role.
Proteins are polymers of amino acids. They are complex organic compounds containing nitrogen, hydrogen, carbon, and oxygen. Proteins are abundant in our everyday food e.g. egg, soya bean, pulses, fish, milk etc.
It is a type of biochemical test which is used to distinguish reducing sugars from non-reducing sugars. This biochemical test is also known as the silver mirror test based on the end product of this test. This test was also used to differentiate between aldehydes and ketones through routine qualitative organic analysis.
The oxidase test is a biochemical reaction that assays for the presence of cytochrome oxidase, an enzyme sometimes called indophenol oxidase. In the presence of an organism that contains the cytochrome oxidase enzyme, the reduced colorless reagent becomes an oxidized colored product .
Bacillus thuringiensis (Bt) is a Gram positive bacteria. It is a spore forming bacteria. It is found naturally in different environment like soil water dead insects and plant surface. It is known for producing special protein crystal during sporulation phase. These protein crystal is known as delta endotoxin (Cry and Cyt proteins). When these crystal … Read more
Nylander’s Test is a chemical test. It is used for qualitative detection of reducing sugar mainly glucose in biological fluids like urine. It was developed in 1880s by Emil Nylander. It was used earlier as screening test for diabetes mellitus and other metabolic disorder. It is based on oxidation reduction reaction. In this test carbohydrate … Read more
Picric Acid Test is a chemical test. It is used for detection of reducing sugar in sample. These reducing sugar are glucose fructose and galactose. It is a highly sensitive assay. It is based on the reducing nature of sugar. The sugar contain free aldehyde or ketone group. This group act as reducing agent in … Read more
The Lane–Eynon method is a volumetric titration technique used for the quantitative estimation of reducing sugars in food and dairy products. It is commonly used for the determination of sugars such as dextrose, maltose, and lactose. This method is based on the reduction of Fehling’s solution by reducing sugars under boiling conditions. It is simple, … Read more
Gerhardt’s test is a type of laboratory test which is performed for the qualitative detection of ketone bodies in urine.
Seliwanoff’s Test is a biochemical colour reaction that is used mainly to distinguish between ketose sugar and aldose sugar. It is performed by using Seliwanoff’s reagent (resorcinol + concentrated hydrochloric acid) and the sugar solution is heated with this reagent. In this test the acid act as dehydrating agent and the reaction is based on … Read more
Benedict’s test is a chemical test that is used to test for the presence of reduced sugars within an analytical test. Thus, simple carbohydrates that contain an aldehyde or free ketone functional group are detected using this test. The test is basing itself upon Benedict’s Reagent (also called Benedict’s solution) which is a complex mix of sodium carbonate, sodium citrate, and the pentahydrate of copper(II) Sulfate.
