Cell Cycle: Definition, Phases, Checkpoints and Regulation
Understand the cell cycle, including G1, S, G2 and M phases, interphase, mitosis, cytokinesis, G0, checkpoints and how cell division is regulated.
Checkpoints in the Cell Cycle – G1, G2, M and Regulation
Checkpoints in the cell cycle regulate DNA replication and division. Understand G1, G2, M, S-phase control, checkpoint proteins, and what happens when they fail.
Membrane Filtration Method for Water Quality Analysis
Membrane filtration method is a laboratory method which is used for estimation of microbial load (bioburden) in liquid sample like drinking water environmental water and pharmaceutical solution. It is a quantitative method and the bacteria are concentrated on a membrane filter and then counted as colony forming unit (CFU). Principle of this method is based … Read more
Heat and Acetic Acid Test for Proteinuria – Principle, Procedure, Result, Uses
What is Heat and Acetic Acid Test? Heat and acetic acid test (heat coagulation test) is a simple qualitative and semi quantitative test which is used for detection of excess protein in urine sample. Mainly albumin is detected but globulin may be present also. It is done as a screening test for proteinuria. Principle of … Read more
Sulphosalicylic Acid Test for Proteinuria – Principle, Procedure, Result, Uses
Sulfosalicylic acid (SSA) test is a simple screening test which is used to detect excessive proteins in urine. It is a rapid and low cost method and it is mainly used for checking proteinuria which indicates kidney impairment. The test is done on clear urine sample after centrifugation so that turbidity is observed clearly. It … Read more
Pauly’s Test – Definition, Principle, Procedure, Uses
What is Pauly’s Test? Pauly’s test is a biochemical colour test which is used for detection of tyrosine and histidine amino acid in proteins. It is a specific colourimetric assay. It was given by Hermann Pauly (German chemist) in 1904. It is based on azo-coupling reaction. In this process sulfanilic acid is diazotized in cold … Read more
PYR (Pyrrolidonyl Arylamidase) Test – Principle, Procedure, Result
PYR test (Pyrrolidonyl Arylamidase test) is a rapid colorimetric biochemical test used in clinical microbiology. It is done for detection of enzyme pyrrolidonyl arylamidase (pyrrolidonyl aminopeptidase) in bacteria. In this test the bacteria is exposed to a synthetic substrate L-pyrrolidonyl-β-naphthylamide. If the enzyme is present the substrate is hydrolyzed and β-naphthylamine is released which is … Read more
Urease Test – Principle, Procedure, Result
Urease test is a biochemical assay used in microbiology to detect whether microorganism produces urease enzyme or not. It is the process in which urea is broken down into ammonia and carbon dioxide by urease enzyme. When urease producing organism is inoculated in urease broth or agar the ammonia is rapidly accumulated and pH is … Read more
Nitrite Reduction Test – Principle, Procedure, Result
Nitrite Reduction Test is a biochemical test, which is used to determine that bacteria can reduce nitrite (NO2−) into other nitrogenous compounds. The nitrite is further reduced to nitric oxide (NO), nitrous oxide (N2O), nitrogen gas (N2) or ammonia (NH3). This test mainly indicates the ability of organism to remove nitrite from medium. In this … Read more
Contribution of Paul Ehrlich and John Snow In Microbiology
Paul Ehrlich Paul Ehrlich (1854–1915) was a German physician, biochemist and scientist. He is regarded as one of the founders of modern hematology, immunology and chemotherapy. His work was mainly concerned with immunity, staining techniques and chemical treatment of diseases. In 1908, he was awarded the Nobel Prize in Physiology or Medicine along with Élie … Read more