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On pages 3687, 3688, and 3689 of the 31 March 2011 issue, there are errors concerning the description of the reference template. In “Methods,” the last sentence reads, “The reference template referred to the allele that showed the lesser positive amplification counts in the sample.” The sentence should have read, “The reference template referred to the wild-type allele.” In Table 2, the description of “m” reads, “Average reference template concentration per PCR well. The reference template referred to the allele with the lesser count in each sample.” The description should have read, “Average reference template concentration per PCR well. The reference template referred to the A allele.” In Tables 3 and 4, the description of “m_r” reads, “Average reference template concentration per PCR well. The reference template referred to the allele with the lesser count in each sample.” The description should have read, “Average reference template concentration per PCR well. The reference template referred to the wild-type allele.”