Diagnosis of Enterocytozoon bieneusi by the polymerase chain reaction in archival fixed duodenal tissue.

This study involved ninety five formalin-fixed paraffin-embedded duodenal biopsy specimens retrieved from hospital files that were microscopically observed for the presence of microsporidia. Eleven samples that revealed compatible organisms were analyzed by the polymerase chain reaction (PCR) with four different protocols for the detection of Enterocytozoon bieneusi. Amplicons of the right size were obtained by at least one method for nine samples, remaining two negative ones. We report a PCR methodology that allows the use of archival specimens obtained for traditional pathology.