Biochemical Test of Mycobacterium tuberculosis

Biochemical Test of Mycobacterium tuberculosis Basic Characteristics Properties (Mycobacterium tuberculosis) 5 % NaCl Tolerance Negative (-ve) 68°C Catalase Test Negative (-ve) Acid Fast Stain Positive (-ve) Acid Phosphatase Negative (-ve) Amidase Test Positive (-ve) Arylsulphatase Test Negative (-ve) Growth at 22°C Negative (-ve) Growth at 25°C Negative (-ve) Growth at 42°C Negative (-ve) Growth at 25°C Negative (-ve) Growth on P-Nitrobenzoic Acid Negative (-ve) Growth on TCH (10 mg/ml) Positive (-ve) Iron Uptake Negative (-ve) Neutral Red Test Positive (-ve) … Read more

Rapid Method for Enumeration of E. coli Biotype I

Rapid Method for Enumeration of E. coli Biotype I

This method is modified by Anderson and Parker. Prepare serial tenfold dilutions in peptone water of food. Aseptically transfer sterile cellulose acetate membranes to the surface or dried glutamate agar. Transfer duplicate 1.0 mL aliquots of each dilution to cellulose acetate membranes, using a sterile glass Drigalski spreader, distribute the fluid over the entire membrane (except the periphery). Incubate plates 4 h at 35°C (facilitate resuscitation). Transfer each membrane to tryptone bile agar plate and incubate for 18 h at … Read more

Biochemical Test of Corynebacterium diphtheriae

Biochemical Test of Corynebacterium diphtheriae

Biochemical Test of Corynebacterium diphtheriae Basic Characteristics Properties (Corynebacterium diphtheriae) CAMP Negative (-ve) Capsule Non-Capsulated Catalase Positive (+ve) Cetrimide Test Negative (-ve) Citrate Negative (-ve) Coagulase Negative (-ve) Flagella Non-Flagellated Gas Variable Gelatin Hydrolysis Negative (-ve) Gram Staining Positive (+ve) H2S Positive (+ve) Hemolysis Weak Beta hemolysis Indole Negative (-ve) Motility Non-Motile MR (Methyl Red) Positive (+ve) Nitrate Reduction Positive (+ve) OF (Oxidative-Fermentative) Fermentative Oxidase Negative (-ve) Pigment Positive (+ve) Shape Rod/Club Shaped Spore Non-Sporing Urease Negative (-ve) Fermentation of … Read more

Biochemical Test of Pseudomonas aeruginosa

Biochemical Test of Pseudomonas aeruginosa

Biochemical Test of Pseudomonas aeruginosa Basic Characteristics Properties (Pseudomonas aeruginosa) Capsule Some Non-Capsulated and Some are encapsulated (Pseudomonas aeruginosa secretes a capsule-like polysaccharide called alginate- Sumita Jain and Dennis E. Ohman 2005) Catalase Positive (+ve) Cetrimide Test Positive (+ve) Citrate Positive (+ve) Coagulase Negative (-ve) Flagella Flagellated (Single) Gas Negative (-ve) Gelatin Hydrolysis Positive (+ve) Gram Staining Negative (-ve) H2S Negative (-ve) Hemolysis Beta Hemolytic Indole Negative (-ve) Motility Motile (Unipolar) MR (Methyl Red) Negative (-ve) Nitrate Reduction Positive (+ve) … Read more

Candida albicans- An Overview

Habitat of Candida albicans Normal Habitat: mucosal membranes of human and other warm blooded animals. Also found in the gut, the vagina or also in the surface of the skin. Found in the digestive tract of birds also. Isolated from soil, animal, hospitals, in-animate objects and food. Worldwide distribution Morphology of Candida albicans Small, oval, measuring 2-4 µm in diameter. Yeast form, unicellular, reproduce by budding. Single budding of the cells may be seen. Both yeast and pseudo-hyphae are gram-positive. … Read more

What is Southern Blotting?

Southern Blot- Principle, Steps and Applications

Southern Blotting Definition The analytical technique that involves the transfer of a specific DNA, RNA or a protein separated on gel to a carrier membrane, for their detection or identification is termed as blotting. The process of transfer of the denatured fragments out of the gel and onto a carrier membrane makes it accessible for analysis using a probe or antibody. Depending upon the substance to be separated, blotting techniques may be – Southern blot, Northern blot or Western blot … Read more

Biochemical Test of Actinomyces israelii

Biochemical Test of Actinomyces israelii Basic Characteristics Properties (Actinomyces israelii) CAMP Negative (-ve) Capsule Non-Capsulated Catalase Negative (-ve) Flagella Negative (-ve) Gelatin Hydrolysis Negative (-ve) Gram Staining Positive (+ve) H2S Positive (+ve) Hemolysis Negative (-ve) Indole Negative (-ve) Motility Non-Motile MR (Methyl Red) Positive (+ve) Nitrate Reduction Positive (+ve) OF (Oxidative-Fermentative) Anaerobic Pigment Negative (-ve) Shape Rod Spore Non-Sporing Urease Negative (-ve) VP (Voges Proskauer) Negative (-ve) Fermentation of Adonitol Negative (-ve) Arabinose Positive (+ve) Cellobiose Positive (+ve) DNase Negative … Read more

Cytokines- Mechanism of action and Functions

Cytokines- Mechanism of action and Functions

Cytokines Cytokines are a family of small proteins that mediate an organism’s response to injury or infection. Cytokines operate by transmitting signals between cells in an organism. Minute quantities of cytokines are secreted, each by a single cell type, and regulatory functions in other cells by binding with specific receptors. Their interactions with the receptors produce secondary signals that inhibit or enhance the action of certain genes within the cell. Unlike endocrine hormones, which can act throughout the body, most … Read more

Habitat and Morphology of Chlamydia trachomatis

Habitat of Chlamydia trachomatis It is an obligate intracellular human pathogens. Humans are the only natural host. It cannot survive outside of a eukaryotic host. Chlamydia trachomatis is transmitted by oral, vaginal or anal sex, and can also be transmitted from mother to newborn during a vaginal delivery. They can cause discharge from the penis, pain and burning during urination, infection or inflammation in the ducts of testicles, and tenderness or pain in the testicles. Morphology of Chlamydia trachomatis It … Read more

Protein Structure- Primary, Secondary, Tertiary and Quaternary

Protein Structure- Primary, Secondary, Tertiary and Quaternary

Four levels of hierarchy in protein conformation can be described. A. PRIMARY STRUCTURE PRIMARY STRUCTURE refers to the order of the amino acids in the peptide chain. 1. The free α-amino group, written to the left, is called the amino-terminal or N-terminal end. 2. The free α-carboxyl group, written to the right, is called the carboxyl-terminal or C-terminal end. B. SECONDARY STRUCTURE SECONDARY STRUCTURE is the arrangement of hydrogen bonds between the peptide nitrogens and the peptide carbonyl oxygens of … Read more