Weak birefringence of the precholesteric liquid crystalline DNA mesophase is illustrated in the photomicrograph presented in this section. The large pitch and relative disorganization of this low-density anisotropic phase is evident in the image. The DNA concentration for this specimen is approximately 150 milligrams per millimeter, and the magnification is approximately 350x. The digital image presented above was originally recorded on Fujichrome 64T transparency film using a Nikon Optiphot-Pol microscope with crossed polarized illumination. Exposures were recorded about 2.5 f-steps under the recommended value given by an in-camera photomultiplier and were push-processed approximately 1.5 f-steps in the first E-6 developer.