Antigens molecules that recognize

Monoclonal antibodies (mAh) are molecules that recognize and bind a specific foreign substance called an antigen. They are produced from a single clone of B lymphocytes. Conventionally, mouse mAh have been generated for experimental and diagnostic use. Techniques have been developed to humanize mouse mAh to facilitate their therapeutic use in humans. It is also now possible to make mAh which are fully human. 

Antibodies are highly specific, binding only to a restricted part of a given antigen known as an epitope. Given the billions of antibody specificities that may be produced by the immune system, an antibody that recognizes an epitope on virtually any molecule may be produced. It is this property that makes antibodies immensely powerful tools for experimental, diagnostic and therapeutic procedures. 

LPS Lipopolysaccharide L-selectin Leucocte selectin, formerly knovm as monoclonal antibody that recognizes murine L-selectin (MEL-14 antigen), leucocyte cell adhesion molecule-1 (LeuCAM-1), lectin cell adhesion molecule-1 (LeCAM-1 or LecCAM-1), leucocyte adhesion molecule-1 (LAM-1)... 

A second type of occultation concerns the relations that exist between biomolecules. In the same way that the antibody nature of an immunoglobulin molecule becomes evident only when its complementary antigen has been recognized, the epitope nature of a set of amino acids in a protein can... 

A common application for (strept)avidin-biotin chemistry is in immunoassays. The specificity of antibody molecules provides the targeting capability to recognize and bind particular antigen molecules. If there are biotin labels on the antibody, it creates multiple sites for the binding of (strept)avidin. If (strept)avidin is in turn labeled with an enzyme, fluorophore, etc., then a very sensitive antigen detection system is created. The potential for more than one labeled (strept)avidin to become attached to each antibody through its multiple biotinylation sites is the key to dramatic increases in assay sensitivity over that obtained through the use of antibodies directly labeled with a detectable tag. 

Paratope The part of an antibody that recognizes the epitope, i.e., that part of the molecule of an antibody that binds to an antigen. 

Where related molecules are recognized by an antibody, they are said to cross-react and such antibodies are likely to be unsuitable for some assays. For example, where measurements of a particular drug are made, metabolites of the drug having similar structures may also react with the antibody. The extent of cross-reactivity may be assessed by comparing the concentration at which a 50% displacement of the related compound is obtained with that required for the antigen (Figure 7.11). 

---