Giardia intestinalis: DNA extraction approaches to improve PCR results

► DNA extraction methods on efficiency of PCR for Giardia in feces were examined. ► Different fecal samples pretreatments and DNA extraction protocols were evaluated. ► The QIAamp Stool Mini Kit is more sensitive than the PCI method for DNA extraction. ► Freeze/thaw cycles and agitating samples with glass beads before using the Kit is recommended.