ssPA-GCaMP6f is a genetically encoded photoactivatable fluorescent Ca[2+] indicator. It consists of the calmodulin-binding peptide M13, a circularly permuted green fluorescent protein and calmodulin. The circularly permuted fluorescent protein is interrupted at residue 145, and is based on EGFP; several mutations which are necessary and sufficient for photoactivation and superfolding have been introduced into the sequence (FBrf0230149).