Sulforhodamine B
# Sulforhodamine B

Sulforhodamine B or Kiton Red 620 $(C_{27}H_{30}N_2O_7S_2)$ is a fluorescent dye with uses spanning from laser-induced fluorescence (LIF) to the quantification of cellular proteins of cultured cells. This red solid dye is very water-soluble.

## Spectroscopy

The dye has maximal absorbance at 565 nm light and maximal fluorescence emission at 586 nm light. It does not exhibit pH-dependent absorption or fluorescence over the range of 3 to 10.

## Applications

Sulforhodamine B is often used as a membrane-impermeable polar tracer or used for cell density determination via determination of cellular proteins (cytotoxicity assay).

