subject: What Are Antibodies? [print this page] Antibodies are proteins made by white blood cells called B lymphocytes or B cells. There are five different types of antibody. They are mostly shaped like a Y, although one type, IgM, is made up of 5 such Y shapes joined together into a star-like shape.
The region at the end of each the two short arms of the Y is known as the antibody binding site. The binding sites are able to fit themselves against particular shapes on other large molecules, like two pieces of a jigsaw being joined together. Each B cell produces antibodies with a unique binding site. Some of the antibodies are present on the surface of the cell, with their binding sites pointing outwards.
When something enters the body from outside, for example bacteria or viruses, a small number of B cells will have antibodies with binding sites that recognise structures on these invaders. The foreign structures are called antigens. When the surface antibodies on a B cell recognise an antigen, this acts as a signal to the cell. It starts to multiply very rapidly and produces a clone of a large number of identical daughter cells. The cells of these clones change in shape and size to become plasma cells. Plasma cells are able to produce large quantities of their particular antibody.
The antibodies bind to their target antigens. This can have several results. For example, it can prevent viruses or bacteria from entering into tissues and causing damage, or it can make it easier for the body to destroy and eliminate the invader.
Antibodies provide scientists with a valuable tool. They are able to use antibodies as specific reagents for a variety of purposes. Suppliers like us as at Novus Biologicals have extensive antibody catalogues from which researchers can select the exact antibodies they require. We have the expertise to cater for the specific needs of researchers.
