Determination of PCR products by CE with contactless conductivity detection

The use of CE with contactless conductivity detection for the determination of PCR products is demonstrated for the first time. The separation of specific length PCR products according to their size could be achieved using 5% PVP as a sieving medium in a separation buffer consisting of 20 mM Tris and 20 mM 2-(cyclohexylamino)ethansulphonic acid (pH 8.5). A fused silica capillary of 60 cm length and 50 μm id and an applied separation voltage of -15 kV were employed and separations could be completed within 20-50 min. PCR amplified DNA fragments of different sizes obtained from different bacterial plasmid templates as well as a fragment from genomic DNA of genetically modified soybeans could be successfully identified.