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.
Atomic Absorption Spectrophotometer (AAS) is an analytical instrument used for finding the concentration of metals and metalloids in a sample. It is a sensitive method. It is mostly used when very small amount of element is present in the sample. The instrument works on the absorption of light by free atoms. The atoms must be … Read more
Color Spectrophotometer is a precise analytical instrument that is used to measure and define the colour of a material. It measures colour by studying the interaction of light with the sample. It gives the colour in numerical form and reduces the error of human eye observation. It works by passing or reflecting a beam of … Read more
Microscope is a scientific instrument which is used to see very small objects that cannot be seen by naked eye. It produces enlarged image of minute objects and their fine details. It is used for observing cells, bacteria, tissues and other microscopic structures. The word microscope is formed from two words. Micro means small and … Read more
Stage micrometer is a special microscope slide which is used for measuring very small objects under the microscope. It is generally like a normal glass slide in size, about 1 by 3 inches, but it has a fine scale marked on its surface. This scale has known true length. It is used as a standard … Read more
Stage micrometer is a special type of microscopic glass slide which is used for calibration and measurement of microscopic objects. It acts like a small ruler on the microscope stage. It has a fine scale marked or engraved on its surface. The scale of stage micrometer has a known measurement. Generally, the total scale is … Read more
Vortex mixer is a laboratory instrument that is used to mix small amount of liquid samples rapidly. It is commonly used for mixing liquids in test tubes, vials, and well plates. It produces a swirling movement in the liquid sample, and this movement is called a vortex. It is made up of an electric motor … Read more
Homogenizer is a mechanical instrument used in laboratory and industry. It is used for mixing, dispersing and breaking down materials. It makes the mixture uniform and homogeneous. Homogenizer works by applying strong mechanical force. These forces include shear, cavitation and turbulence. By these forces, particles or droplets become smaller in size. It is used for … Read more
Incinerator is a special type of furnace used for burning waste materials. It is used for hazardous and non-hazardous wastes. The burning is done in a controlled combustion chamber at very high temperature. The process is called incineration. In this process, different wastes like solid garbage, soil, sludge, liquids and gases are burned. After burning, … Read more
Laboratory hot plate is a portable table top instrument used for heating samples, chemicals and reagents. It gives heat slowly and safely. It is used instead of open flame. It has a flat heating surface. The surface may be made up of ceramic, aluminium, polypropylene or stainless steel. A heating element is present below the … Read more
Laboratory refrigerators and freezers are special cooling instruments used in research, medical and scientific laboratories. They are used for storing temperature sensitive materials. Biological samples, vaccines, chemicals and reagents are preserved in them. They are different from normal household refrigerators. Laboratory refrigerators and freezers are made for accurate and stable cooling. They have uniform cooling, … Read more