FabuLight™ - Fab Labeling Primary Antibodies with Fluorophore-Conjugated Fab Anti-Fc

For certain applications it may be convenient to Fab-label primary antibodies prior to incubation with cells or tissue. This can be accomplished by complexing the primary antibody with a dye-conjugated Fab anti-Fc antibody (either anti-IgG, Fcγ specific or anti-IgM, μ chain specific). Because the labeled Fab fragment is monovalent the complex does not precipitate, and binding to the Fc portion of the primary antibody leaves the antigen binding region active. Fab anti-Fc antibodies are also useful for labeling cell surface immunoglobulins without cross-linking and activating B cells, or for labeling Fc chimeras (fusion proteins).