Simplified recording microspectrophotometer.

Most of the recording microspectrophotometers described to date are laboratory-built instruments utilizing a carefully designed optical train and dynode feedback to the photomultiplier tube. We describe in this report a simplified recording microspectrophotometer designed to eliminate the above two requirements. In addition, improvements in electronic circuitry due to the use of solid-state operational amplifiers are described. A capability for use in visual pigment studies is demonstrated.