Isotype Controls are antibodies of the same host species, isotype, and conjugate as the primary antibody of interest, but with no specific target antigen. As essential background controls, they distinguish specific signals from non-specific noise.
Their key functions include eliminating Fc receptor-mediated non-specific binding, establishing baseline thresholds for positive signals, validating antigen specificity, and assisting in optimizing antibody concentrations.
Widely used in flow cytometry, immunofluorescence, IHC, in vivo studies, and ELISA, isotype controls are standard components for ensuring reliable results in immunoassays.
Immunoglobulin A (IgA) is the most abundant immunoglobulin in body fluids and the second most abundant immunoglobulin in plasma, found at a concentration of 0.4 to 2.2 mg/ml. It plays a very important role in the first specific defense against natural infection. Secretory IgA differs from serum IgA in that it contains two additional peptides: the secretory component and the J chain.