Standardised allele amplification efficiency. The amplification efficiency is estimated for each ‘putative allele’ by maximum likelihood and represented by a blue dot. Each dot is connected by a vertical line to the full horizontal line representing efficiency 1.0, which was defined using the first allele (Desu-DRB*001) as a reference (see text for details). The dashed horizontal line represents an efficiency of two, which could represent duplicated or homozygous alleles. ‘Low efficiency putative alleles’ are not represented (Desu-DRB*009a, Desu-DRB*053b, Desu-DRB*053c).