Calcium indicator GCaMP6f lentivirus is a preparation of highly purified lentiviral particles ready-to-use for monitoring calcium signal in virtually any type of mammalian cells. Calcium is a universal second messenger regulating essential cellular signaling events in a broad range of tissues and organisms. GCaMP is one of the most widely used calcium indicators in neuronal imaging and calcium cell biology. When calcium is present, fusion calcium indicator undergoes a conformational change and GFP fluorescence is activated from quenched status. The newly developed GCaMP6 shows superior brightness and ultrasensitivity to calcium concentration change. This lentivirus expresses the fast version of GCaMP6 (GCaMP6f) under the control of the Synapsin 1 promoter, with Hygmycin as a selection marker.