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.
Immune response is a protective response of body against harmful foreign agents. It is done by physical barriers, immune cells and chemical signals. It helps to maintain normal health of body. The main function of immune response is to identify and destroy pathogens, foreign toxins and abnormal cells. It also removes damaged cells from body. … Read more
Antigen processing and presentation is a biological mechanism by which the immune system detect the foreign antigen and abnormal cell. It is important for activation of T lymphocytes. It helps in formation of specific adaptive immune response against pathogen. In this process, the foreign antigen such as viral protein, bacterial protein or abnormal cellular protein … Read more
Major Histocompatibility Complex (MHC) molecules are glycoproteins present on the surface of cells. These are encoded by a large group of genes. In human, these genes are present on chromosome 6 and are called Human Leukocyte Antigens (HLA). The main function of MHC molecules is to bind short peptide fragments and present them on the … Read more
Hematopoiesis is a continuous physiological process by which all mature blood cells and bone marrow cells are formed. It is an essential process for maintaining normal blood cell number in the body. This process starts from pluripotent hematopoietic stem cells (HSCs). These stem cells are mainly present in the soft spongy tissue of bone marrow … Read more
ELISA (Enzyme-Linked Immunosorbent Assay) is a sensitive laboratory test used for detection of antigen, antibody, protein, peptide and hormone from biological samples. It is based on the specific binding between antigen and antibody. So the particular substance present in the sample can be detected by this reaction. In this test, the sample or target molecule … Read more
Antibodies are Y-shaped glycoproteins. These are also called immunoglobulins. It is important component of adaptive immunity. These are produced by B-lymphocytes. After activation, B-cells are changed into plasma cells. These plasma cells produce large amount of antibodies against foreign substances. The foreign substance is called antigen. Antigen may be bacteria, virus, toxin or any other … Read more
Antibody or immunoglobulin (Ig) is a specific glycoprotein produced by B-lymphocytes and plasma cells. It is produced in response to entry of foreign substance in the body. These foreign substances are called antigens. Antibody is an important part of humoral immunity. It is used to identify and bind with bacteria, viruses, toxins and other harmful … Read more
Indirect ELISA (Enzyme-Linked Immunosorbent Assay) is a sensitive laboratory method used to detect specific antibody present in a biological sample like serum. It is called indirect because the enzyme is not attached with the primary antibody. The enzyme is attached with the secondary antibody, which detects the primary antibody. In this test, a known antigen … Read more
Immunogenicity is the inherent ability of a substance to produce an immune response inside the body. It may be a vaccine, biotherapeutic drug, therapeutic protein, or any foreign substance. It is mainly related with the recognition of that substance by the immune system. During this process, the body can form antigen-specific humoral response and cellular … Read more
Lymphocytes are a type of white blood cells (WBCs) and comes under agranulocytes. These are one of the main cells of immune system. They protect body from foreign antigen and infection. They are present about 20-40% of total circulating white blood cells. These cells move through blood and lymphatic system. During this movement they find … Read more