Inverse-Pericam(T148.Q67) is a genetically encoded fluorescent Ca[2+] indicator. It is an inverse pericam, being composed of the calmodulin-binding peptide M13, a circularly permuted green fluorescent protein and Xenopus calmodulin. Inverse-Pericam(T148.Q67) was generated by mutagenesis of Ratiometric-Pericam, by introducing the mutations D148T and E67Q (FBrf0192802).