Fast-GCaMP-RS08 is a genetically encoded fluorescent Ca[2+] indicator with fast kinetics. It consists of a calmodulin-binding peptide, a circularly permuted green fluorescent protein and calmodulin. Fast-GCaMP-RS08 was derived by mutagenesis of GCaMP3, containing in addition the mutations T412Q and L414T (FBrf0222168). For detailed kinetic and spectral properties, see FBrf0222168.