PCR reactions were performed in a final volume of 8.0 L; each reaction contained EraGen MC PCR solution 35 (prod. no. PN1235 or PN1305 for the 579T system; Clinical Chemistry 50, No. 11, 2004 EraGen), 0.4 L of 20ϫ EraGen CFTR PCR primer mixture, 1ϫ Titanium Taq, and 1 L of diluted genomic target DNA. Reactions were cycled according to the following profile: 1 cycle of 30 s at 95°C, and 40 cycles of 1 s at 95°C, 10 s at 55°C, and 30 s at 72°C. Each of the primer mixtures contained forward and reverse primers for a subset of the mutations at concentrations of 100 -200 nM.