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.
Repetitive sequence-based PCR (rep-PCR) is a molecular technique used to produce genetic fingerprint of bacteria and fungi. It is used for identification and classification of microorganisms at species, subspecies or strain level. It is based on the presence of repetitive DNA sequences in microbial genome. These sequences are non-coding and occur in many copies. In … Read more
Nanoparticle-Assisted PCR (nanoPCR) is an advanced modification of Polymerase Chain Reaction (PCR) in which small nanoparticles are added into the PCR reaction mixture. These nanoparticles are usually 1-100 nm in size and they help in better amplification of DNA. It is used to increase the efficiency, sensitivity, specificity and speed of the PCR reaction. Gold … Read more
Types of PCR Here is the list of Types of PCR based on different categories; 1. Conventional PCR Conventional PCR is the basic type of PCR in which target DNA is amplified by repeated temperature cycles. It is also called end-point PCR or traditional PCR. In this method, detection of amplified DNA is done only … Read more
PCR Machine is an automated laboratory instrument that is used to amplify small segment of DNA or RNA into millions or billions of copies. It is also known as thermal cycler or DNA amplifier. It contains a thermal block where reaction tubes containing sample, primers, nucleotides and polymerase enzyme are placed. The machine changes the … Read more
Electroporator is a specialized electronic pulse generator that is used to deliver controlled high-voltage electrical pulses to biological cells. It is used in electroporation process for temporary opening of the cell membrane. It acts on the lipid bilayer membrane of the cell and makes small aqueous pores for short time. Through these pores, different macromolecules … Read more
Micropipette is a laboratory instrument that is used to measure and transfer very small volume of liquid in microliter range. It is highly accurate instrument and commonly used in molecular biology, chemistry and clinical diagnostic laboratory. It works by a piston mechanism which creates suction and draws liquid into a disposable plastic tip. The volume … Read more
Chromatography is a laboratory analytical technique which is used to separate a chemical mixture into its individual components. It is used for identification, purification and estimation of different substances present in a mixture. It separates the components according to their different movement through two phases. In this technique, the mixture is distributed between a mobile … Read more
Spectrophotometer is an analytical instrument which is used to measure the light absorbed, transmitted or reflected by a substance at particular wavelength. It has a light source, sample holder and detector. The liquid sample is kept in a cuvette. Then the beam of light is passed through the sample. The detector detects the light which … Read more
Single Use Bioreactor is a cell cultivation system where the reusable glass or stainless steel vessel is replaced by a disposable plastic bag. It is also known as Disposable Bioreactor. The bag is pre-sterilized and used only for one batch. This flexible polymeric bag acts as the sterile place for the growth of cells. It … Read more
Tissue Homogenizer is a laboratory device that is used to break biological tissues into small and uniform particles. It physically disrupts the tissue structure by rupturing the cell wall and cell membrane. During this process, intracellular components like proteins, nucleic acids (DNA and RNA) and microorganisms are released from the tissue matrix. The uniform mixture … Read more