FIG. 4.

Real-time PCR genotyping of C. parvum using SYBR Green I fluorescence. A polymorphic 319-bp fragment of the GP900 gene (2) was amplified by PCR in the presence of SYBR Green I. Shown are the melting peaks for type 1 isolates 2066-K (37), TU502, and CDC728 and type 2 isolates 7C (10), TAMU (25), and JRLHIV. The differences in melting peak temperatures between the type 1 and the type 2 isolates were statistically significant at the 0.001 level. The cursors were positioned manually and are labeled with the respective C. parvum type.