FIGURE 2.
Purification of human rod outer segments over discontinuous sucrose gradients. Left: Absorption spectra of human rhodopsin in rod outer segments before sucrose gradient purification. The presence of rhodopsin is indicated by the difference in the absorption reading at 498 nm before and after light exposure. The A280/A498 ratio indicates the sample is still impure. Right: Absorption spectra of human rhodopsin in rod outer segments after discontinuous sucrose gradient purification. The A280/A498 ratio indicates a higher degree of purity.