Red-shifted Cameleons for live-cell imaging of intracellular Ca²⁺ signals

Red-shifted Cameleons are FRET-based Ca²⁺ biosensors that consist of a green donor and an orange or red acceptor fluorescent protein, respectively. The probes are optimized for measuring Ca²⁺ in the cytosol, in the mitochondrial matrix or in the lumen of the endoplasmic reticulum. The higher  excitation wavelength of red-shifted cameleons (~ 480 nm) allows a combination with UV-excitable chemical indicators such as fura-2 for simultaneous real-time imaging of Ca²⁺ dynamic within organelles and the cytosol in a ratiometric manner.

Here we provide transfection-grade Red-shifted Cameleons for the Cytosol, Mitochondria and the Endoplasmic Reticulum (ER):