their ability to differentiate homozygous genotypes

at the human b-globin sickle cell locus. The melting transition was monitored by including the dye LCGreen Plus in the tify single nucleotide polymorphisms in amplicons up to 1 kb in length.9–11 Different PCR products have melting temperatures (Tm’s) based on their se-Keywords: LCGreen, high-resolutionPCR, and the data were uniformly analyzed with custom in-house software. The wild-type and mutant homozygous genotypes differed by a theoretical Tm of 0.09 C and were best discriminated by the high-resolution HR-1 instrument. All instruments could identify a double single nucleotide polymorphism heterozygote by the heteroduplexes formed. However, signal-to-noise ratios varied from 260 to 3500, suggesting that melting instrument design (data acquisition, data density, thermal quence, length, and GC content.2 Nearly all homo-zygous sequence changes have a shift in Tm compared with the wild-type sample.12,13 In a previous study,8 we compared nine different instruments that could be used for DNA melting analysis. In general, 96-well plate instruments per-formed suboptimally because of temperature differ-ences across the plate. Furthermore, not all instruments could be heated at the same rate: some instruments required only a few minutes for melting, whereas others required over an hour. In the current study, we selected only those instruments that could heat continuously at 0.1C/s, and also eliminatedmelting, mutation scanning, amplicon genotypingInstrument Compa