Sourav Pan is the founder and sole author of Biology Notes Online. He holds a Bachelor of Science (B.Sc.) degree and an M.Sc. in Microbiology from the University of Calcutta. He creates educational resources covering microbiology, immunology, biotechnology, genetics, cell biology, botany, zoology, and other life-science subjects.
His goal is to make complex biological concepts easier to understand through well-structured, student-friendly articles based on academic textbooks, peer-reviewed research, and authoritative scientific sources. In addition to writing new content, he regularly reviews and updates articles to improve their accuracy, clarity, and educational value.
Triple beam balance is a mechanical instrument used for measuring the mass of an object. It does not need electricity. So it can be used in ordinary laboratory and classroom. It measures mass, not weight. So the reading is not changed by local gravity like weight. The mass is measured by balancing the object with … Read more
Analytical balance is a sensitive laboratory instrument used for measuring very small mass with high accuracy. It is commonly used in chemistry, biology, pharmaceutical and research laboratory. It can measure mass up to 0.1 mg or 0.01 mg level. So it is used when accurate weighing of sample is needed. Small change in air, dust … Read more
Reversed-Phase Chromatography (RPC) is a type of liquid chromatography used for separation and analysis of compounds. It separates molecules mainly according to their hydrophobic nature. In this method the stationary phase is non-polar. The stationary phase is usually silica gel attached with hydrophobic alkyl chains. Common phases are C18 and C8. The mobile phase is … Read more
Liquid Chromatography is a separation technique used to separate, identify and measure the components of a liquid mixture. It is used in analytical chemistry for the analysis of complex samples. In this technique, the sample is passed through a column with the help of a liquid solvent. The liquid solvent is called mobile phase. The … Read more
Hydrophobic Interaction Chromatography (HIC) is a chromatographic technique used for separation and purification of proteins, peptides, enzymes and monoclonal antibodies. It separates molecules according to their surface hydrophobic nature. In this method the stationary phase has hydrophobic groups attached to it. These groups may be phenyl, butyl, octyl or other alkyl groups. These groups bind … Read more
Flash chromatography is a rapid preparative chromatographic technique used for separation and purification of mixture of organic compounds. It separates compounds mainly on the basis of their polarity and their different interaction with stationary phase and mobile phase. It is a modified form of column chromatography. In normal column chromatography, the solvent moves slowly by … Read more
Two-Dimensional Immunoelectrophoresis is a technique used for the analysis and quantitation of mixture of proteins or antigens in a complex sample. It is also called Crossed Immunoelectrophoresis (CIE). It is mostly used for serum, tissue extract, microbial homogenate and other biological sample. In this technique the separation is done in two directions. In the first … Read more
Immunoelectrophoresis is a biochemical analytical technique used for separation and identification of proteins in biological sample. It combines two process, electrophoresis and immunodiffusion. It is mainly used for detection of serum proteins, immunoglobulins and other antigenic substances. In this method, the antigen mixture is first placed in agarose gel. Then electric current is passed through … Read more
Polyacrylamide Gel Electrophoresis (PAGE) refers as a biochemical technique used for separation of proteins, nucleic acids etc. according to their charge and size. In this method, separation is done by migration of charged molecules through a gel matrix. The gel matrix is polyacrylamide gel. It act as a molecular sieve. The principle is based on … Read more
SDS-PAGE is a Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis. It is a laboratory technique used for separation of proteins according to their molecular weight. It is widely used in biochemical and molecular biology laboratory for protein analysis. In this method, protein sample is treated with SDS and heat. The SDS is an anionic detergent which denature … Read more