Structural periodicities observed in mammalian rod outer segments with Nomarski optics

Structural periodicities have been observed in isolated rod outer segments of several mammalian species using differential interference contrast (Nomarski) optics. The spacing among the observed structural inhomogeneities is somewhat variable. If these measured spacings are corrected for shrinkage, estimated by comparing ROS widths in unfixed cells to those in light microscopic autoradiographs, the mean values correlate well with published rates of ROS renewal in rats and dogs.