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.
Hematocrit centrifuge is a laboratory instrument used for separation of blood components. It works by high speed centrifugal force. The blood sample is kept in narrow capillary tube and then it is rotated very fast. During centrifugation, the heavier red blood cells (RBCs) move to the bottom of the tube. The plasma remains at the … Read more
Native PAGE is a gel electrophoresis technique used for separation of proteins and nucleic acids. It is called native because the molecule remains in its natural form. The protein is not unfolded during the process. In this method, SDS, urea and reducing agents are not used. So the protein keeps its original charge, shape and … Read more
Bioreactor is a special vessel or system used for growing living cells. It is used for microorganisms, plant cells and animal cells. It gives controlled condition for their growth and activity. In bioreactor, temperature, pH, oxygen level and nutrients are controlled properly. Due to this, the cells grow in suitable condition. The metabolic activity of … Read more
Microtome is an instrument used to cut very thin sections of tissues and other materials. These thin sections are used for microscopic examination. The sections are generally about 1 to 100 micrometer in thickness. The word Microtome is derived from Greek words. Mikros means small and temnein means to cut. So microtome means an instrument … Read more
Spectrophotometer cuvette is a small transparent tube like laboratory vessel that is used to hold liquid, gas or solid sample during spectroscopic analysis. It is derived from French word cuvette, meaning little vessel. It may be square or circular in cross-section and has straight sides. It has at least two parallel and optically clear windows. … Read more
pH meter is an instrument used to measure the acidity or alkalinity of a solution. It gives the value of pH directly. It is mainly used for aqueous solution. It works like a sensitive voltmeter. It measures the voltage difference produced between two electrodes. One is pH glass electrode and another is reference electrode. The … Read more
Gradient PCR is a modified type of Polymerase Chain Reaction used to find the best temperature for a PCR reaction. It is mainly used for finding the proper primer annealing temperature. In normal PCR, all the tubes get the same temperature. But in gradient PCR, different temperatures are made in different rows or columns of … Read more
Bright Field Microscope is a simple optical microscope that uses visible white light to observe the specimen. It is also known as compound light microscope. It is the most commonly used microscope in biology, medicine and laboratory works. In this microscope, light is passed from below the specimen. The light travels through the specimen and … Read more
Ocular Micrometer is a precision measuring instrument used in microscope for measuring microscopic objects. It is also known as eyepiece micrometer or reticle. It is used to measure the length, width and diameter of very small objects which are seen under microscope. It is a small circular glass disc which is placed inside the eyepiece … Read more
Toolmakers Microscope is a precision optical instrument that is used to measure and inspect the small mechanical components. It is also known as measuring microscope. It is mainly used to observe the shape, size, angle and position of small parts without touching the surface. It consists of an optical head, rigid vertical column, heavy base … Read more