Effects of different PMA concentrations on detecting live and heat-killed C. parvum oocysts. Live or heat-killed C. parvum oocysts were incubated with 0.5, 5, 50, or 150 μM PMA for 10 min followed by 2 min of light exposure. This was followed by the extraction of genomic DNA and PCR amplification with primers targeting the SSU rRNA gene (A) or the hsp70 gene (B). PCR products were analyzed using an Agilent Bioanalyzer 2100. M, marker; −, no PMA control; Δ, oocysts treated at 70°C for 30 min; C, PCR control that lacks a template.