AMCA (7-amino-4-methylcoumarin-3-acetic acid) labeled Goat Anti-Human Kappa Chain Antibody excites in the near ultraviolet (350 nm) and emits a visible bright blue fluorescence at about 450 nm. This antibody has been optimally labeled with AMCA to provide the brightest label for fluorescence microscopy. This chain-specific antibody is produced specifically to distinguish between chains or classes of target immunoglobulins. This antibody is affinity-purified and treated by negative solid-phase adsorption to remove cross-reacting antibodies. This chain specific antibody has virtually no cross-reactivity with other immunoglobulin classes or other heavy or light chains. This fluorochrome conjugate can be employed in flow cytometry or used for tissue staining.