Preparation of antibody conjugates

Enzymes, fluorochromes and other marker molecules are commonly used in a variety of applications to provide specific detection signals. To this aim, they may be conjugated to antibodies, avidin, protein A or G and other proteins in many ways. Fundamental work on chemical modification of proteins and antibody labelings has already been done long before AH COONS and co-workers employed those techniques for the preparation of their first fluorescent antiboy conjugates. A popular way to prepare conjugates was to make use of aromatic isocyanates: the phenyl groups become linked through carbamide bonds with the εamino groups of the lysine residues in the protein.