GCaMP5G is a genetically encoded fluorescent Ca[2+] indicator that consists of the calmodulin-binding peptide M13, a circularly permuted green fluorescent protein and calmodulin. GCaMP5G was derived by mutagenesis of GCaMP3, containing in addition the mutations T302L, R303P and D380Y (FBrf0219564). For detailed kinetic and spectral properties and a comparison of GCaMP5G with other GCaMP series sensors, see FBrf0219564 and FBrf0235079.