Online microbiology notes by SAGAR ARYAL
Cystine Tryptic Agar Cystine tryptic agar (CTA), also known as cystine trypticase agar, was developed by Vera as a semi-solid growth medium used for the identification and maintenance of microorganisms for extended periods when stored at appropriate temperatures. It is used for the detection of bacterial motility and, with added carbohydrate, it contributes to fermentation … Read moreCystine Tryptic Agar
Counter Current Immunoelectrophoresis Immunoelectrophoresis refers to the process in which an antigen mixture is first separated into its component parts by electrophoresis and then tested by immunodiffusion. The electrophoresed antigen mixture in agarose gel allows the separation of different antigens along the gel slide, and then the lateral diffusion of an antibody in the gel … Read moreCounter Current Immunoelectrophoresis
Cystine Glucose Blood Agar Cystine Glucose Blood Agar is known as Cystine Heart Agar. Francis developed blood-dextrose-cystine agar after determining F. tularensis would only grow on an artificial medium supplemented with sulfhydryl compounds (i.e., cystine). F. tularensis is a fastidious organism and requires cysteine for best growth. To recognize the lifetime achievements of Francis in understanding … Read moreCystine Glucose Blood Agar
Biochemical Test of Lactobacillus spp. Image Source: Creative Market and India Mart. Some of the characteristics are as follows: Basic Characteristics Properties (Lactobacillus spp.) Capsule Negative (-ve) Catalase Negative (-ve) Citrate Negative (-ve) Flagella If present, peritrichous Gas Negative (-ve) Gelatin Hydrolysis Negative (-ve) Gram Staining Gram positive H2S Negative (-ve) Indole Negative (-ve) Motility … Read moreBiochemical Test of Lactobacillus spp.
Potassium hydroxide (KOH) test Objective To visualize the fungal element in the clinical specimens. To examine skin scrapings or flakes and hair for the presence of hyphae and arthroconidia in suspected dermatophyte infections. Principle Potassium hydroxide (KOH) can be used on clinical specimens to clear cellular material and for better visualization of fungal elements. KOH … Read morePotassium hydroxide (KOH) test
Ouchterlony Double Immunodiffusion technique Immuno-diffusion is a technique for the detection or measurement of antibodies and antigens by their precipitation which involves diffusion through a substance such as agar or gel agarose. Simply, it denotes precipitation in gel. It refers to one of the several techniques for obtaining a precipitate between an antibody and its … Read moreOuchterlony Double Immunodiffusion technique
Enteroinvasive E. coli (EIEC) Enteroinvasive E. coli (EIEC) strains are rare in both developed and developing countries. EIEC infections are characterized by a period of watery diarrhea that precedes the onset of scanty dysenteric stools containing blood and mucus. Pathogenic strains are primarily associated with a few restricted O serotypes: O124, O143, and O164. EIEC … Read moreEnteroinvasive E. coli (EIEC)
Plate Count Agar (PCA) Plate count agar (PCA) is a bacteriological substrate used for determination of the total number of live, aerobic bacteria in a sample. It is not a selective medium. The amount of bacteria is expressed as colony forming units per gram (CFU/g), in solid samples and per ml (CFU/ml) in liquid samples. … Read morePlate Count Agar (PCA)
Plasmodesmata- Structure and Functions Every living cell in a higher plant is connected to its living neighbours by fine cytoplasmic channels, each of which is called a plasmodesma which passes through the intervening cell walls. They act like tunnels running through the cell wall which allow communication with the other cells in a tissue. The … Read morePlasmodesmata- Structure and Functions
Morphology of Bacteria Morphologically bacteria can resemble: Cocci (Singular: coccus) Bacilli (rods) (Singular: rod, bacillus) Vibrios (Singular: vibrio) Spirilla (Singular: spirillum) Spirochaetes (Singular: spirochaete) Cocci These are round or oval bacteria measuring about 0.5–1.0 um in diameter. When multiplying, cocci may form pairs, chains, or irregular groups: cocci in pairs are called diplococci, e.g. meningococci … Read moreMorphology of Bacteria