Funds are requested by eight NIH-funded investigators to establish a powerful and flexible imaging system equipped with patch clamp capability and a rapid solution change system. The primary need is to measure intracellular Calcium ion concentration using fluorescent indicators at video rates, although other ions will also be measured. All of the projects arise directly from the investigators' currently funded projects. There is no such system at the Health Sciences Center. Approximately half of the investigators are familiar with such equipment from other institutions. The others have been acutely aware of the benefits arising from the application of such analysis to their investigations. The Dean of the School of Medicine and three department Chairpersons are highly committed to establishing this facility. The facility will serve not only to allow continued insightful contributions from a productive group of investigators, but it will serve as a focus for similarly minded investigators of cellular signaling in the Denver area.