FIG. 2.

Sensitivity of RT-PCR for simultaneous detection of Giardia and IPC (A), C. parvum with CHSP1 and CHSP4 primers (B), and C. parvum PCR with CPHSP2423 and CPHSP2764 primers (C) as determined by silver-stained polyacrylamide gel electrophoresis. Lanes 1 to 6 in all panels represent 50 liters of river water (100-μl packed pellet) spiked with approximately 1,000, 100, 50, 10, 1, and 0 cysts or oocysts; lanes 7 and 8 in panel A show positive and negative RT-PCR controls, respectively. Lanes M, DNA molecular weight markers (φX174 HaeIII). IPC was spiked at a concentration of 10 fg per sample.