Sequences of two mutated cDNAs generated with the primer-sets a-K474R and a-R476K using the double-primer PCR method. The primer sets are listed in Table 1. The mutated residue and the two neighboring residues are shown on top of the DNA sequence. For each primer set, the top DNA sequence is the normal sequence, and the bottom sequence is the sequence of the mutated plasmid. The mutated bases are shown in lower case and red color. Each tandem repeat of the primer is marked with a different background-color and numbered in roman numerals. Note that in the color-marked regions, a few bases are missing from the ends of the primer-copies. These few bases apparently participated in primer-primer annealing. Sequence traces from the ABI Sequencer are shown only for two repeats of the primers to allow visualization of the direct sequencing result. The roman numerals below the traces relate to the roman numerals of the repeats in the respective sequence above the trace.