Elimination of multiple amplicons. Only the 700 channel is shown. Box indicates a cut DNA strand corresponding to a single nucleotide polymorphism that was identified and sequenced from both undigested and digested templates. A) Filled arrowheads indicate multiple bands in every lane of an eight-fold pool plate. These spurious cut products were derived from CJE digestion of heteroduplexes formed between PCR products from co-amplified targets, presumably homeologs. B) The same template pools from (A) digested with ApaI prior to PCR amplification for TILLING. Ovals denote cut DNA strands corresponding to single nucleotide polymorphisms that were identified only when TILLING from digested template. Open arrowheads show the position of bands from CJE digestion that represent polymorphisms present in more than one member of the population.