Rapid dimethyl sulfoxide-modified acid-fast stain of Cryptosporidium oocysts in stool specimens.

A rapid dimethyl sulfoxide modification of an acid-fast technique was applied to direct fecal smears to monitor cryptosporidiosis in nonhuman primates. Brilliantly stained pink oocysts against a pale green background demonstrated well-preserved internal morphology and facilitated rapid, simple, noninvasive diagnosis without fluorescent or phase-contrast microscopy.