High-Contrast Fluorescence Imaging Using new Optical Switches and Optical Lock-in Detection Imaging Microscopy

Abstract

We have developed a new microscope imaging technique to isolate specific fluorescence signals from background signals by using lock-in detection of the modulated fluorescence of a unique class of optical probe. This optical lock-in detection (OLID) approach involves modulating the fluorescence emission of an optical switch probe through defined optical manipulation of its fluorescent and non-fluorescent states - a digital lock-in detection method is employed to isolate the modulated signal of interest from non-modulated signals in the sample, such as conventional fluorescent probes and natural fluorophores. I will discuss the spectroscopic and photochemical properties of several new synthetic and genetically-encoded optical switches and illustrate their applications in high contrast (OLID) imaging studies of specific structures and proteins in cultured cells and in living organisms.