Active Motif's ProStain Protein Quantification Kit simplifies the determination of cell extract protein concentrations by providing highly sensitive detection reagents that are easy to use. The dye used in ProStain is resistant to many commonly found contaminants in cell lysis buffers such as detergent and salt, which limit the usefulness of other protein quantification systems. And, the spectral properties of ProStain change greatly after it is bound, effectively eliminating any background from unbound dye.