Mechanism of crystallization of purified human midcycle cervical mucus

The crystallization phenomenon of human midcycle cervical mucus was studied with purified mucin and sodium chloride. The drying of the purified mucin in saline was subjected to stress by the use of an air curtain, and crystallization (fern pattern) was found to follow the stress. Lithium chloride and calcium chloride were not compatible with the mucin for the formation of fernlike crystals. When a dilute solution of mucin dissolved in saline was dried, a radial crystallization pattern was observed to emanate from a single crystal in the center. Upon closer examination, the pattern was observed to emanate from the corners of the crystal.