Accurate compensation is crucial to effective multicolor analysis in flow cytometry. Often, however, cellular-based compensation controls are not completely effective as many antigens are not highly expressed, and dimly stained cells can lead to inaccurate compensation settings. To address this issue, Invitrogen is pleased to introduce the AbC™ anti-Mouse Bead Kit (A10344) for use with all isotypes of mouse immunoglobulin. Each kit provides polystyrene microspheres that are either coated with Ig (positive compensation beads) or uncoated (negative compensation beads). After mixing with a fluorophore-conjugated mouse antibody, the two components provide a distinct high signal positive control with an appropriate negative population that can then be used to set compensation properly regardless of the intensity of the cells in the actual experiment. Invitrogen's AbC™ anti-Mouse Bead Kit demonstrates the highest and most consistent reactivity to the different subclasses of immunoglobulin in the industry.