Figure 1.

Comparison of fractional rhodopsin bleaching estimated by calculation and bleaching measured by MSP (n = 3). Fractional bleaching was calculated according to Equation 1. Measurements of the extent of bleaching were made by measuring MSP spectra of a few tens of rod outer segments projecting from the edge of a flat-mounted retina. Measurements were made before and after exposure to a calibrated bleaching light. The amount of rhodopsin bleached by each light exposure was then calculated as the difference in absorbance at 500 nm from spectra measured before and after bleach exposure, as described in Materials and Methods. Error bars are ±SEM. The solid line drawn at a slope of 1 indicates perfect correspondence of calculated to measured values.