What is Rapid Plasma Reagin (RPR) Test? Principle of Rapid Plasma Reagin (RPR) Test The principle of the Rapid Plasma Reagin (RPR) test is based on the detection of antibodies produced in response to antigens released by damaged host cells during a syphilis infection. The RPR test is a macroscopic, non-treponemal flocculation card test that … Read more
What is Mantoux Test? Principle of Mantoux Test The Mantoux test operates on the principle of delayed-type hypersensitivity, specifically Type IV hypersensitivity. This test is designed to assess a person’s cell-mediated immunity against the bacterium Mycobacterium tuberculosis. To conduct this test, a substance known as Purified Protein Derivative (PPD) is used, which is essentially a … Read more
What is Neutralization Test? Principle of Neutralization The neutralization principle is based on the understanding that certain antibodies or antitoxins can reduce or neutralize the various biological effects caused by enzymes, toxins, and viruses. There are two main types of neutralization tests: In both types of neutralization tests, the goal is to assess the ability … Read more
What is Complement Fixation? Principle of Complement Fixation Test The principle of the complement fixation test is based on the interaction between antigens, antibodies, and complement proteins. When an antigen and antibody come into contact, they form an antigen-antibody (Ag-Ab) complex. This complex then interacts with complement proteins and becomes fixed with them. As a … Read more
Such is the case with the slide and tube Widal test. The agglutinins against the ‘0’ (somatic) and ‘H’ (flagellar) antigens of Salmonella typhi, paratyphi A, and paratyphi B are measured qualitatively (slide test) and quantitatively (Tube test) using a suspension of suitable organisms that have been killed. Widal-quantitative tube agglutination test This test aids … Read more
What is Hemagglutination assay? Haemagglutination Test Principle The fundamental principle underlying the hemagglutination test revolves around the interaction between antigens and antibodies present on the surface of Red Blood Cells (RBCs). When these antigens encounter their corresponding complementary antibodies or vice versa, they bind together, resulting in the agglutination or clumping of the RBCs. This … Read more
The nucleic acids of many viruses encode surface proteins (such as hemagglutinin (HA) of influenza virus) that agglutinate red blood cells (RBC) of numerous species. Hemagglutination is the process by which viral hemagglutinins react with red blood cells to form a lattice of agglutinated cells that settle unevenly in a tube or microtiter well. Unagglutinated … Read more
What is Anion Exchange Chromatography? Principle of Anion Exchange Chromatography The principle of anion exchange chromatography is based on the net surface charge of proteins, which changes with the pH and is determined by their isoelectric point (pI). The pI of a protein is the pH at which it carries no net charge. Below the … Read more
What is Cation Exchange Chromatography? Cation Exchange Chromatography Principles The principles of cation exchange chromatography are based on the net surface charge of proteins and the concept of isoelectric point (pI). The net surface charge of a protein can change with the pH of the surrounding environment. The pI of a protein refers to the … Read more
What is Sandwich ELISA? Sandwich ELISA Principle The principle of sandwich ELISA involves the detection of antigens using a combination of specific antibodies. The test begins by coating and immobilizing a known antibody onto the wells of a microtiter plate. This immobilized antibody serves as the capture antibody, which will bind to the antigen of … Read more
