Electrophoretic analysis of 5B12 and 1G09 microsatellites. DNA was amplified from the isolates shown in the presence of 5′ 32P-labeled reverse primer, resolved on a sequencing gel, and visualized by autoradiography. (A) 5B12 locus; (B) 1G09 locus. Genotype 2 isolates are italicized. The host origins of GCH1, MD, and UCP oocysts are indicated in panel B. The positions of selected markers from a 10-bp ladder are shown at the right. neg., negative PCR control.