Biocheminsider Overview Cobalt is a hard ferromagnetic, silver-white, hard, lustrous, brittle element. It is a member of group VIII of the periodic table and is located between iron and nickel and shares many chemical and physical properties with these two elements. Cobalt is found in the Earth’s crust only in a chemically combined form. Cobalt … Read more
Overview Potassium sulfide is an inorganic salt that is not found as an isolated compound in nature. It always found as a mixture with potassium hydrosulfide. It is a colorless crystal with a typical sulfur smell. Potassium sulfide can be prepared through the reaction of pure carbon with potassium sulfate at high temperatures. Potassium sulfide … Read more
Gas chromatography is the most widely used form of chromatography in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Gas chromatography is used to separate complex mixtures of different molecules based on their physical properties such as polarity and boiling point. The other uses of gas chromatography include: Testing purity … Read more
Overview Polyphosphoric acid (H3PO4) is a colorless, odorless and highly viscous liquid compound with strong hydroscopic properties. It is a mixture of linear phosphoric acids and orthophosphoric acid. Phosphoric acids with less than 95% H3PO4 (68% P2O5) contain the simple orthophosphoric acid. However, at higher concentrations, the acid consists of a mixture of ortho, pyro, … Read more
By Prof Walter Jaoko Introduction What Is Mannitol Salt Agar? Mannitol salt agar or MSA is a commonly used selective and differential growth medium in microbiology. It encourages the growth of a group of certain bacteria while inhibiting the growth of others. This medium is important in medical laboratories as one method of distinguishing pathogenic microbes in a short period of time. It contains a … Read more
By Prof Walter Jaoko Introduction What Is XLD Agar? Xylose Lysine Deoxycholate agar (XLD agar) is a selective growth medium used for the isolation and differentiation of Enterobacter, especially Salmonella and Shigella species from food, environmental samples and clinical specimens.The agar was developed by Welton Taylor in 1965. It has a pH of approximately 7.4, leaving it with a bright pink or red appearance due to the indicator phenol red. Sugar fermentation lowers … Read more
By Prof Jeremiah Seni Introduction Pour plate method is usually the method of choice for counting the number of colony-forming bacteria present in a liquid specimen. In this method, fixed amount of inoculum (generally 1 ml) from a broth/sample is placed in the center of sterile Petri dish using a sterile pipette. Molten cooled agar … Read more
By Prof Mariam M Mirambo Introduction In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria. Samples can then be taken from the resulting colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested.The Aim of this method is to obtain … Read more
By Prof Mariam M Mirambo Introduction Endospore Staining is a technique used in bacteriology to identify the presence of endospores in a bacterial sample, which can be useful for classifying bacteria.Within bacteria, endospores are protective structures used to survive extreme conditions, but this protective nature makes them difficult to stain using normal techniques such as simple staining and Gram staining. Special techniques for endospore … Read more