Compensation beads are critical components in flow cytometry. As flow cytometry evolves to accommodate increasingly complex experiments involving multiple fluorescent markers, the need for accurate compensation for spectral overlap becomes paramount. 

In flow cytometry, multiple fluorescent dyes are often employed simultaneously to label different cellular markers. However, many fluorophores have overlapping emission spectra, which can lead to fluorescence spillover. This phenomenon occurs when the signal from one fluorochrome contaminates the signal from another, resulting in inaccurate data interpretation. 

Compensation beads are specially designed particles that help researchers calibrate their flow cytometers to correct for this spectral overlap. Typically made from polystyrene and coated with antibodies specific to certain markers, these beads can be labeled with various fluorochromes. When mixed with fluorochrome-conjugated antibodies in a controlled manner, they create distinct populations that mimic the behavior of actual cells.The primary purpose of these beads is to establish compensation settings on the flow cytometer. By running samples of compensation beads alongside experimental samples, researchers can determine the degree of spillover between different channels. This allows for precise adjustments in the instrument settings to ensure that each fluorescent signal is accurately attributed to its corresponding marker.