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.
Serological pipette is a long graduated pipette used in laboratory to measure and transfer liquid in ml range. It is commonly used for 1 ml to 50 ml volume transfer. It is mostly disposable plastic (polystyrene) and sometimes glass. It has clear graduation markings on the body to monitor the liquid level during measuring. It … Read more
Pipette (Glass Pipettes) is a laboratory instrument made up of a narrow glass tube that is used to measure and transfer a specific volume of liquid from one container to another. It works by creating a suction or partial vacuum above the liquid (using pipette bulb or mouth suction) so the liquid is drawn inside … Read more
Laboratory equipment is the different tools, instruments and devices used in a laboratory for doing experiments and research work. It is used to measure, observe and handle samples, chemicals and biological specimens in a proper way. It includes measuring instruments, heating and cooling devices, glassware and plasticware, sterilization equipment, microscopes, separation devices, safety equipment and … Read more
Autoclave validation is needed to prove that the autoclave is consistently giving effective sterilization of materials to a required Sterility Assurance Level (SAL). Sterility cannot be guaranteed only by testing the finished product. So, the process has to be validated and documented. Validation is done to check the correct physical parameters like temperature, pressure, and … Read more
A simple microscope is an optical device consisting of a single convex lens that magnifies objects by enlarging their image through light refraction. Simple Microscope is a simple optical instrument used to magnify very small objects so that they can be seen by the unaided eye. It is mainly a single convex lens (mostly double … Read more
pH meter is an instrument used to measure pH of a solution. It measures the hydrogen ion activity in water based solution. It is used to know whether solution is acidic or alkaline. It works on potentiometry principle. It measures the difference in electrical potential between a measuring electrode and a reference electrode. The measuring … Read more
HPLC (High-performance liquid chromatography) is a liquid chromatography technique used to separate, identify and quantify different components present in a liquid mixture. It is also called high-pressure liquid chromatography. It is used when accurate separation is needed in a mixture. In this technique, a liquid solvent is used as mobile phase and the column is … Read more
Diaphragm of a microscope is a thin opaque disc like part having a circular opening (aperture) which can be adjusted. It is fitted in the light path of microscope, mostly below the stage and near the condenser. It controls the passage of light that will go to the specimen. The main work of diaphragm is … Read more
UV-Vis spectroscopy (Ultraviolet-visible spectroscopy) is an analytical technique used to measure the amount of ultraviolet and visible light absorbed or transmitted by a chemical sample. It measures light in UV and visible region. The reading is taken as absorbance or transmittance. This technique relies on interaction between electromagnetic radiation and matter. When molecules are exposed … Read more
UV-Visible (UV-Vis) spectroscopy is an analytical technique used to measure the absorption or transmission of ultraviolet and visible light by a sample. It works in UV region (about 190–400 nm) and visible region (about 400–800 nm). It is a fast and simple method used in both qualitative and quantitative analysis. The absorption is recorded as … Read more