Nonspecific binding charged groups

Fig. 5.1 Sources of nonspecific binding. Incubation with antibodies should have only antibody binding to the correct antigen. Nonspecific binding can result from charged groups that bind proteins including antibodies. The tissue can have Fc receptors that bind to the Fc region of any antibody. Some tissues can have exposed antibodies...

The difficulties that arise from nonspecific binding of incubated antibodies to charged groups, Fc receptors, and endogenous antibodies are major problems for immunocytochemistry (Fig. 5.2). 

Charged groups are the most common nonspecific sites for binding of antibodies (Fig. 5.2). Charged groups are normal on proteins or lipids and sometimes the result... 

Fig. 5.2 Examples of nonspecific antibody binding. During immunocytochemistry incubations nonspecific binding occurs. The correct antigen will bind the primary antibody correctly. Charged groups will bind to any protein or antibody such as the 1° antibody. The Fc receptor will bind the first antibody that comes in contact here with the 1° antibody. Any endogenous antibodies are likely to bind only to secondary antibodies made against the species of the animal...

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