The Marine Sciences Research Center at SUNY Stony Brook will acquire new instrumentation to upgrade a specialized seagoing microscope system for quantitative epifluorescence and microspectrophotometry. The microscope system is operated and maintained as a shared use facility. Funds will be used to purchase hardware and software for the computer that controls the microscope, a VCR for time-lapse research, a video camera, and a controller unit. The equipment will be maintained for use by all investigators and it will especially benefit NSF-sponsored research concerning species specific growth rates of phytoplankton, single cell pigment content, DNA content, bacterial counts, binding of fluorescent antibodies, and micro-distribution of oxygen.