Use of a gain-modulating framing camera for time-resolved imaging of cellular phenomena

A gain modulating framing camera and its application towards the study of real time cellular phenomena is described. Based on a unique operating principle, this framing camera can be modulated by over 90% at 1 GHz. The camera consists of an image converter with a pair of deflection electrodes and a rectangular aperture. Since a sinusoidal electric field is applied to the deflection electrodes, the photoelectron image- forming beam is continuously deflected and swept on the aperture. A bias is applied to center the sweep of the photoelectron beam on the edge of the aperture. The gain modulating with high depth can hence be accomplished. We are now constructing a fluorescence lifetime imaging microscope system employing this gain modulating frame camera based on the phase domain method. Such high depth modulation enables us to achieve frequency signals as low as 1 Hz in heterodyne operation. We describe examples of application of the system towards the observation of various cellular phenomena.