Modulated electron multiplied fluorescence lifetime imaging microscope: all solid state camera for fluorescence lifetime imaging
Abstract. We have built an all solid state camera that is directly modulated at the pixel level for frequency domain fluorescence lifetime imaging microscopy (FLIM) measurements. This novel camera eliminates the need for an image intensifier through the use of an application specific charge coupled device design in a frequency domain FLIM system. The first stage of evaluation for the camera has been carried out. Camera characteristics such as noise distribution, dark current influence, camera gain, sampling density, sensitivity, linearity of photometric response, and optical transfer function have been studied through experiments. We are able to do lifetime measurement using our modulated, electron multiplied fluorescence lifetime imaging microscope (MEM FLIM) camera for various objects, e.g. fluorescein solution, fixed green fluorescent protein (GFP) cells, and GFP actin stained live cells. A detailed comparison of a conventional microchannel plate (MCP) based FLIM system and the MEM FLIM system is presented. The MEM FLIM camera shows higher resolution and a better image quality. The MEM FLIM camera provides a new opportunity for performing frequency domain FLIM.
Journal of biomedical optics