A solid-state microscope (SSM) for quantitative microscopy in image cytometry has been designed to optimize spatial, photometric, and spectral resolution. The SSM is an optoelectronic device for scanning and viewing microscopic objects in the visible light spectrum. Using Kohler illumination, pulsed light is transmitted through the microscope sample and focused by a single objective lens. The objective magnifies and projects the image onto a large-area charge-coupled device (CCD) located at the intermediate focal plane. Flexibility in scanning of the sample and optical considerations require a CCD array of >1000 X1000 picture elements, with each element having a sensing area of approximately 7 Am X7 um. The signals from the picture elements are directly digitized and mapped on a one-to-one basis into a large-frame memory at a rate of approximately 20 Mbytes/s. The entire digital image is continuously displayed in real time on a monochrome monitor at a rate of >60 Mbytes/s. The images stored in the frame memory can also be accessed by an external image processing system for quantitative measurements. The main features of the SSM are its simple optical path, high resolution, large field of view, image display of the image on a monitor with overlay graphics for object labeling, direct access to any part of the digital image, different scanning modes includ-ing full-frame scanning and time delay integration, spectral imaging, and large dynamic (sensitivity) range.