FIGURE 4.

Detection of Apo-opsin in Human Retina Extracts. (A) The spectral scan of rhodopsin in the extract of an eye exposed to a bright flash of light was measured before and after the addition of 11-cis retinal, (before, red line; after 2 min, blue line; after 20 min, green line) and following bleaching with bright light (purple line). Regeneration of rhodopsin is seen as an increase in absorption at 498 nm (blue arrow). (B) The difference spectrum was taken by subtracting the scan taken 20 minutes after the addition of 11-cis retinal from the scan taken after light exposure (purple line), illustrating the typical rhodopsin peak at 498 nm. The conversion of 11-cis retinal to all-trans retinal after bleaching is detected as a negative deflection at 380 nm.