Flagella are the complex filamentous cytoplasmic structure protruding through cell wall. These are unbranched, long, thread like structures, mostly composed of the protein flagellin, intricately embedded in the cell envelope. Cilia are slender, microscopic, hair-like structures or organelles that extend from the surface of nearly … Read more
S.N. Characteristics Gram Positive Gram Negative 1 Gram Reaction Retain crystal violet dye and stain blue or purple Can be decolorized to accept counterstain (safranin) and stain pink or red 2 Cell Wall Cell Wall is 20-30 nm thick. Cell Wall is 8-12 … Read more
Bacteria are prokaryotic, unicellular microorganisms, which lack chlorophyll pigments. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles. Due to the presence of a rigid cell wall, bacteria maintain a definite shape, though they vary … Read more
It is the differential staining techniques which was first developed by Ziehl and later on modified by Neelsen. So this method is also called Ziehl-Neelsen staining techniques. Neelsen in 1883 used Ziehl’s carbol-fuchsin and heat then decolorized with an acid alcohol, and counter stained with … Read more
Glycolysis is the metabolic process that serves as the foundation for both aerobic and anaerobic cellular respiration. In glycolysis, glucose is converted into pyruvate. Glucose is a six- memebered ring molecule found in the blood and is usually a result of the breakdown of carbohydrates into … Read more
Hemolysis is the breakdown of red blood cells (RBC). A substance that causes hemolysis is a hemolysin. Brown (1919) introduced three terms alpha, beta and gamma to indicate three types of streptococci based on haemolytic reactions observed on blood agar plates. Beta-hemolytic Streptococci Beta-hemolysis (β-hemolysis) is … Read more
Blood Agar (BA) are enriched medium used to culture those bacteria or microbes that do not grow easily. Such bacteria are called “fastidious” as they demand a special, enriched nutritional environment as compared to the routine bacteria. Blood Agar is used to grow a wide … Read more
Antibody (Ab) also know as Immunoglobulin (Ig) is the large Y shaped protein produced by the body’s immune system when it detects harmful substances, called antigens like bacteria and viruses. The production of antibodies is a major function of the immune system and is carried out by a … Read more
The eventual death toll from the massive earthquake that struck Nepal on April 25 will be unbearable. The death toll from Saturday’s deadly 7.9 magnitude quake and a series of aftershocks that struck various parts of Nepal has reached 4347 leaving 8154 injured as of Tuesday morning. … Read more
Polymerase Chain Reaction (PCR) is a powerful method for amplifying particular segments of DNA, distinct from cloning and propagation within the host cell. This procedure is carried out entirely biochemically, that is, in vitro. PCR was invented by Kary Mullis in 1983. He shared the Nobel Prize … Read more
Introduction of Flagella Flagella are the complex filamentous cytoplasmic structure protruding through cell wall. These are unbranched, long, thread like structures, mostly composed of the protein flagellin, intricately embedded in the cell envelope. They are about 12-30 nm in diameter and 5-16 µm in length. They … Read more
Introduction to Coagulase Test Coagulase test is used to differentiate Staphylococcus aureus (positive) which produce the enzyme coagulase, from S. epidermis and S. saprophyticus (negative) which do not produce coagulase. i.e Coagulase Negative Staphylococcus (CONS). Principle of Coagulase Test Coagulase is an enzyme-like protein and causes plasma to … Read more
Nutrient Agar is a general purpose, nutrient medium used for the cultivation of microbes supporting growth of a wide range of non-fastidious organisms. Nutrient agar is popular because it can grow a variety of types of bacteria and fungi, and contains many nutrients needed for the bacterial growth. … Read more
Normal Laboratory Values: Blood, Plasma, and Serum Test Specimen Conventional Units SI Units Acetoacetate Plasma < 1 mg/dL < 0.1 mmol/L Acetylcholinesterase (ACE), RBC Blood 26.7–49.2 U/g Hb — Acid phosphatase Serum 0.5–5.5 U/L 0–0.9 μkat/L Activated partial thromboplastin time (aPTT) Plasma 25–35 sec — … Read more
Microbiology is the study of microorganisms like bacteria, virus, fungi, protozoans which is seen only under the microscope and which have many economic importance. These are the world top 50 Microbiology Colleges and Universities on the basis of: Global research reputation, Regional research reputation, Publications, … Read more
Light Microscope Electron Microscope Illuminating source is the Light. Illuminating source is the beam of electrons. Specimen preparation takes usually few minutes to hours. Specimen preparation takes usually takes few days. Live or Dead specimen may be seen. Only Dead or Dried specimens are seen. Condenser, … Read more
Gram Staining is the common, important, and most used differential staining techniques in microbiology, which was introduced by Danish Bacteriologist Hans Christian Gram in 1884. This test differentiate the bacteria into Gram Positive and Gram Negative Bacteria, which helps in the classification and differentiations of microorganisms. … Read more
Uric acid crystals invariably form in acidic urine, typically with a urine pH < 5.5. Uric acid is soluble in alkaline urine, preventing the precipitation of urate crystals. The inability of uric acid to crystallize at urine pH > 7.0 is the rationale for urinary alkalinization in patients at … Read more
Habitat Mucous membrane of the upper respiratory tract of humans. Found in the nasopharynx of approx. 75% of healthy peoples. Cell Morphology Slender, short, gram negative rods or coccobacillus 3-0.5 um X 0.5-1 um with rounded ends. Prolonged counterstaining for 5-15 minutes with very dilute … Read more
Ebola Virus do not replicate through any kind of cell division; rather, they use a combination of host and virally encoded enzymes, alongside host cell structures, to produce multiple copies of viruses. These then self-assemble into viral macromolecular structures in the host cell. The virus … Read more
Symptoms may appear anywhere from 2 to 21 days after exposure to Ebola, but the average is 8 to 10 days. Ebola Zaire kills people quickly, typically 7 to 14 days after symptoms appear. A person can have the virus but not show any symptoms … Read more
Ebola Virus are generally approximately 80 nm in diameter, 970 nm long. They are cylindrical/tubular, and contain viral envelope, matrix, and nucleocapsid components. The virus generally appears in a long, filamentous form, but it can also be “U-shaped,” in the shape of a “6” (the … Read more
Basic Characteristics Properties (Vibrio cholerae) Capsule Non-Capsulated Citrate +ve Flagella Flagellated Gas -ve Gelatin Hydrolysis +ve Gram Staining -ve H2S -ve Hemolysis Beta Hemolysis Indole +ve Motility Motile MR (Methyl Red) -ve Nitrate Reduction +ve Oxidase +ve Shape Rods Spore Non-Sporing String Test +ve Urease … Read more
1. They are aerobic and facultative anaerobes. 2. They grow best at 37 degree Celsius. 3. Group D grow well at between 10 degree Celsius and 45 degree Celsius. 4. Growth is poor on solid media or broth. 5. Grow well in media containing blood … Read more