A multichannel microspectrophotometer for visual pigment investigations

The microspectrophotometer described replaces the photomultiplier of conventional scanning systems with a multichannel detector. By eliminating scanning-related artifacts, particularly those associated with mechanical vibrations, this system makes possible ship-based microspectrophotometric studies of visual pigments of marine organisms too fragile for live transport to shore-based laboratories. The performance of the multichannel microspectrophotometer is compared with that of conventional scanning systems and absorbance spectra taken at sea on isolated rhabdoms from Euphausia pacifica are presented. Difference spectra gave a lambda max for rhodopsin of 483 nm and a lambda max for metarhodopsin of 489 nm.