A gradual transition from blue to purple shades in the focal conic texture of this liquid crystalline DNA specimen are indicative of a very shallow thickness gradient. Note the yellow spots with a red outline in some portions of the texture, which are evidence of gas bubbles in the specimen. The DNA concentration for this specimen is approximately 400 milligrams per millimeter, and the magnification is approximately 200x. 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.