Impact of gradient profile on the retention and separation efficiency of primers and amplicons labeled with FAM (blue), HEX (green), NED (yellow), and ROX (red), respectively. Column, monolithic PS/DVB, 60 × 0.2 mm i.d.; mobile phase, 100 mM TEAA at pH 7.0; gradient, (a) 11.75% acetonitrile for 8 min, 11.75%–16.0% acetonitrile in 10 min, (b) 11.75%–16.0% acetonitrile in 10 min, (c,d) 12%–16.4% acetonitrile in 7.0 min; flow rate, 2.0–3.0 μL/min; effective temperature, 58°C; detection, LIF, emission monitored at 525, 555, 580, and 605 nm, respectively; injection volume, 1 μL each; sample, MDR1, blue, exon22, 320 G>A heterozygote; green, MDR1, exon 13, 291 T>C heterozygote; yellow, MDR1, exon 26, 325 T>G and 346 T>C double heterozygote; and red, MDR1, exon 26, 212 C>T and 346 T>C double heterozygote.