Example of the validation procedures employed. A: Electropherogram of the direct sequencing of a cDNA PCR product. Starting with the NAGNAG AS site at position 132 the two alternatively spliced sequence signatures are overlaid. B: FAM fluorescence intensity peaks of the two splice variants (length difference three nucleotides). The lower peak constitutes 40% of the area (ar) of the bigger one, i.e. an approximate ratio of 3:1.