Fig. 2.

Accumulation of endogenous isorhodopsin in long-term dark-adapted Rpe65^-/- mice. Absorption spectra of the endogenous pigment of 2-month-old cyclic-light-reared Rpe65^-/- mice that were then maintained in the dark for 4 weeks (trace i) and of age-matched WT mice with identical light treatment (trace ii) are shown. Spectra represent the difference spectrum of 1% dodecylmaltoside extractions of two retinae before and after bleaching with white light in the presence of NH₂OH (20 mmol/liter). Arrows indicate the respective λ_max. Abs, absorbance; KO, knockout.