Resin-purified digoxigenin-labeled DNA probes: an efficient protocol for mapping and fingerprinting sugarcane

Nonradioactive Southern blotting using digoxigenin (DIG) has become routinely applied to the analysis of single-copy genes for genetic mapping because it is fast and safe. Previous studies indicate that DIG-labeled probes are suitable for single-gene detection in less complex genomes, but their efficient application to mapping a large octoploid genome has not been discussed. We developed a stream-lined procedure for nonradioactive restriction fragment length polymorphism mapping and DNA fingerprinting of sugarcane that combines DIG-11-dUTP and anion-exchange chromatography. In this report, we show that anion-exchange chromatography provides a reliable and simple technique for the resin-purification of large numbers of DIG-labeled DNA fragments 0.3-3.0 kb in size, and it is essential in minimizing contaminants and nonspecific signal.