Nat. Biotechnol. 21, 194–197 (2003)

In the second paragraph of Experimental protocol on page 197, a 'g' (highlighted in bold below) was omitted from the forward primer. The sequence should have read as follows:

Forward: 5′-ggA TCC TAA TAC gAC TCA CTA TAg ggA gAC CAC CATg ggC TAC ACC gAC ATC gAg ATg AAC CgC CTg ggC AAg gTT TCT CCA TAC Agg TCA Cgg ggA gCC-3′