Biochemical Test of Bacteria Biochemical reactions are very important in the identification of bacterial isolates and in the identification of different bacterial species. These tests depend on the presence of certain enzymes, such as catalase, oxidase, urease, gelatinase, etc., produced by the bacteria. Different bacteria produce varying spectra of enzymes. For example, some enzymes are … Read more Biochemical Test of Bacteria
Sensitivity and Specificity When developing diagnostic tests or evaluating results, it is important to understand how reliable those tests and therefore the results obtained are. By using samples of known disease status, values such as sensitivity and specificity can be calculated that allow its evaluation. Therefore, when evaluating diagnostic tests, it is important to calculate … Read more Sensitivity and Specificity
Peptone Water Peptone water is formulated as per Shread, Donovan, and Lee. It is a broth medium used for the growth of the organism and a base for determining carbohydrate fermentation patterns of non-fastidious organisms. In addition, it is also used for the detection of indole production by the organism. Composition Ingredients Gms / L … Read more Peptone Water
Koch’s postulates and its limitations Koch’s postulate forms the very basis of the pathogenic microbiology. The causality of almost all infectious diseases is based on the postulate and theories developed by Robert Koch, who is rightly called the “father of pathogenic microbiology,” and his contemporaries. Developed in the late 19th century, it has stood the … Read more Koch’s postulates and its limitations
Degradation and Deterioration Nature has always provided, in considerable amounts and variety, polymeric materials with interesting compositions and structures. These natural polymers include polysaccharides, such as cellulose, chitin, starch, alginate, galactan, hyaluronic acid, dextran, and gellan, obtained from plants, animals, and microbial sources and polyesters, such as poly(b-hydroxybutyrate) and poly(b-hydroxybutyrate-co-b–hydroxyvalerate), produced by numerous bacteria. In biological … Read more Degradation and Deterioration
General Aseptic Techniques in Microbiology Laboratory Aseptic technique is a set of routine measures that are taken to prevent cultures, sterile media stocks, and other solutions from being contaminated by unwanted microorganisms (i.e., sepsis). While such actions are sometimes called “sterile technique,” that terminology is appropriate only in reference to preventing the introduction of any … Read more General Aseptic Techniques in Microbiology Laboratory
Direct Microscopic Counts Studies involving the analysis of materials including food, water, milk, and, in some cases, air require quantitative enumeration of microorganisms in the substances. Many methods have been devised to accomplish this, including direct microscopic counts, use of an electronic cell counter such as the Coulter Counter, chemical methods for estimating cell mass … Read more Direct Microscopic Counts
Classification of Protozoa The sub kingdom Protozoa which was originally included in the kingdom protista includes unicellular, non-photosynthetic, eukaryotic microorganism that are considered single celled, The Protozoan Animals. The Protozoa may be defined as ‘microscopic, acellular animalcules existing singly or in colonies without tissues and organs, having one or more nuclei. When in colonies, they … Read more Classification of Protozoa
Darkfield Microscopy Microbiology, the branch of science that has so vastly extended and expanded our knowledge of the living world, owes its existence to Antoni van Leeuwenhoek. In 1673, with the aid of a crude microscope consisting of a biconcave lens enclosed in two metal plates, Leeuwenhoek introduced the world to the existence of microbial … Read more Darkfield Microscopy
Bacterial and Fungal Preservation Methods Biopreservation is the process of preserving the integrity and functionality of cells. Most bacteriological laboratories maintain stock cultures of microorganisms for educational, research, bioassay, industrial, or other purposes. A wide variety of techniques are available for the preservation of bacteria and it may be difficult to choose a method for a … Read more Bacterial and Fungal Preservation Methods