Rapid methods to isolate Cryptosporidium DNA from frozen feces for PCR

The polymerase chain reaction (PCR) offers one of the most sensitive method s for detecting Crytosporidium parvum but its sensitivity in fecal material can be greatly reduced by a variety of poorly defined 'inhibitors'. Method s that separate the parasitic oocyst from fecal material prior to DNA extra ction circumvent inhibitor interference but are problematic for frozen spec imens since 'intact' oocysts are required for separation. We report here a relatively low-cost, rapid method for extracting C parvum DNA from frozen f ecal materials that can be used in a PCR assay for detection of single para sitic oocysts. (C) 2001 Elsevier Science Inc. All rights reserved.