Real-time analysis of intracellular glucose and calcium in pancreatic beta cells by fluorescence microscopy

► We examine changes in the intracellular glucose concentration in pancreatic beta-cells by a FRET based technique. ► We show that the FLII12Pglu-700µ-δ6 sensor and fura-2 can be used to analyze glucose and calcium at the same time. ► Glucose is not a pacemaker of oscillations in pancreatic beta-cells. ► Glucose enables intracellular calcium oscillations in pancreatic beta-cells by a KATP channel independent pathway.