No, beads or labels are not required since the system separates the particles based on the intrinsic physical properties when in the presence of Levitation Agent, gravitational forces and magnetic forces.
But adding a stain or some other label that can be detected in the 2 channels can be safely used and can add helpful and additional visual information.
Fluorescent Channel 1 (Green) has an excitation peak at 474 nm and emission peak at 524 nm. Example dyes are Calcien and GFP.
Fluorescent Channel 2 (Red) has an excitation peak at 560 nm and emission peak at 628 nm. Example dyes are PI and Cy3.5.