OXIDASE TEST Meaning and
Definition
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The oxidase test is a biochemical technique used to determine the presence of certain enzymes called oxidases in a microorganism. It is primarily employed in microbiology laboratories to differentiate between different types of bacteria and to identify specific strains.
In this test, a reagent called tetramethyl-p-phenylenediamine dihydrochloride is applied to a strip of filter paper or a cotton swab. An isolated colony of the microorganism under investigation is then smeared onto the paper or swab and observed for any color change. If the microorganism possesses the enzyme oxidase, it will cause the reagent to oxidize, resulting in a color change from colorless to blue or purple.
The oxidase test is widely used in the identification of bacteria, particularly those belonging to the family Neisseriaceae, which includes important genera such as Neisseria, Moraxella, and Acinetobacter. Specifically, it helps to differentiate between oxidase-positive bacteria (producing a positive color change) and oxidase-negative bacteria (no color change).
The presence or absence of oxidase within a microorganism is an important characteristic used to narrow down the identification of bacteria and facilitate their classification. This simple, yet valuable test aids in the preliminary identification of organisms and is a crucial step in the process of microbial characterization and diagnosis.
Etymology of OXIDASE TEST
The word "oxidase" in the term "oxidase test" has its roots in the Greek language. It is derived from the Greek word "oxys", meaning "acid", and "dazein", meaning "to burn". The suffix "-ase" in "oxidase" indicates an enzyme, which is a substance that facilitates chemical reactions. Therefore, the term "oxidase" refers to an enzyme involved in oxidation reactions.
The "oxidase test" is a biochemical test used in microbiology to determine the presence of the enzyme oxidase in microorganisms. This test detects the activity of cytochrome c oxidase, an enzyme involved in the electron transport chain in bacteria. The term "oxidase test" was likely coined based on the premise that this test helps identify the presence or absence of the oxidase enzyme.
