SCAS (4-Sulfonato calix[8]arene, sodium salt) is a quencher developed by Biotium to reduce background fluorescence when using our fixable AM dyes, SynaptoGreen and SynaptoRed dyes. Unlike ADVASEP-7, SCAS dramatically lowers background fluorescence as soon as it is added to the preparation without the need for repeated wash steps.    Off-white solid soluble in water  C56H40Na8O32S8  MW 1665.34