Every day, more researchers are using tunable diode lasers for three- or four-color cytometry. Our AlignFlow flow cytometry alignment beads are designed for diode laser–excited research, including the calibration and focusing of flow cytometers. These 2.5-µm BODIPY dye–labeled microspheres are excitable between 630 and 660 nm with emission in the range of 670-720 nm.