What's the distinction between immunoglobulin and antibody?

Immunoglobulin refers to animal proteins which have antibody activity. They mainly exist in plasma, and are also found in other body fluids, tissues and secretion. Immunoglobulin in human plasma mostly exists in the gamma globulin (γ- globulin). Immunoglobulin can be divided into five classes as IgG, IgA, IgM, IgD and IgE. Speaking of proteins, now various recombinant human proteins are developed.

Antibodies are immunoglobulin produced by plasmocytes which are differentiated by B cells under the stimulation of antigenic materials, and they can have specific binding reaction with the corresponding antigen. Because initially it was proved through electrophoresis that antibody activity was in γ-globulin part in serum, so it is referred to as two kinds of (γ) globin. It turned out that not all antibodies are in γ zone; and globulin located in γ zone is not necessary to have the antibody activity.

In 1964, the World Health Organization held a special meeting, stating to refer to globulins with antibody activity and antibody-related globulins collectively as immunoglobulin (Ig), such as serum of patients with macroglobulinemia and cryoglobulinemiaserum show abnormal immune globulin as well as immunoglobulin subunits of "normal people" and the like. Thus, "immunoglobulin" is structural and chemical concept, while "antibody" is a biological and functional concept. We can say that all antibodies are immunoglobulin, but not all immunoglobulin are antibodies. And proteins which can result from the expression of recombinant DNA within living cells are recombinant proteins.

1. The specific binding antigen: the difference between antibody and other immunoglobulin molecules lies in that antibody is capable of specifically binding with the corresponding antigen to cause physiological or pathological effects in the body; it can produce a variety of direct or indirect visible antigen-antibody binding reaction in vitro. Antibodies relay on specific binding sites on its molecules to bind with antigen.

2. The activation of the complement: after the antibody bind with the corresponding antigen, they make use of the exposed complement binding site to activate the complement system, complement lysis and cytolytic immune function and so on.

3. The binding to the cell: immunoglobulin of different classes can have combination with different types of cells to produce different guilt and involve in immune responses.

4. be able to go through the placenta and mucous membranes: immunoglobulin G (IgG) can go into the fetal bloodstream through the placenta to make the fetal form a natural passive immunity. Immunoglobulin a (IgA) can go through the digestive tract and respiratory mucosa, and it is the main factor of mucosal topical anti-infection immunity.

5. with antigen: antibody molecule is a kind of protein and also has the performance of stimulating the body to produce an immune response. Different immunoglobulin molecules each have a different antigenicity.

6. The resistance of antibody to physical and chemical factors is not the same to general globulin: not heat-resistant and destroyed under 60 ~ 70 ℃. Various enzymes and substances which make proteins coagulated and denatured both can destroy the role of antibody. Antibodies can be precipitated by neutral salts. In the production, globulin containing antibody is usually precipitated from immune serum with the use of sodium sulfate or ammonium sulfate, and then purify it through dialysis method. Flarebio offers different kinds of superior recombinant proteins such as recombinant Stim2.