Extraction of microsporidial DNA from modified trichrome-stained clinical slides and subsequent species identification using PCR sequencing.

Molecular techniques involving polymerase chain reaction (PCR) and sequencing provide a relatively simple and objective means of identifying microsporidia to species level. We modified previously described methods of DNA extraction and PCR conditions for identification of microsporidia from museum slides, clinical specimens and environmental samples and successfully identified Vittaforma corneae in 11 out of 13 cases of microsporidial infection from used trichrome-stained slides of corneal scrapings from HIV-negative patients with keratoconjunctivitis.