Multi-User Equipment approved in grant 13/08769-1: imaging system for optical measurements of the redox state and membrane potential

Abstract

The imaging system for optical measurements of redox state and membrane potential is essential equipment for the experiments proposed in the Thematic Project No. 2013/08769-1. This system is constituted by an inverted microscope with lasers, dichroics mirrors, emission filters and a high speed and quantum efficiency camera, coupled to a laser beam bender and a patch-clamp amplifier to correlate the imaging data with electrophysiological measurements. The laser beam bender in a critical angle of incidence allows excitation of the cytoplasm at few nanometers deep from the plasma membrane - the evanescent field. This permits the real time imaging of fluorescent structures adjacent to the plasma membrane, such as secretory granules containing fluorescent probes, and thus the precise evaluation of exocytosis. Moreover, the same system may also be used in open field mode to evaluate the redox state as well as the membrane potential of pancreatic islet cells with specific probes. This system will also be made available to the Brazilian scientific community users, after training and under supervision by the technical team in charge for the equipment. The booking for its usage and training will be available through the website of CEFAP-ICB/USP. (AU)