Hybridization of extension products in each 10-L reaction was performed by mixing 40 L of EraGen MC Hyb Solution A (prod. no. PN1237; EraGen Biosciences) and 0.25 L of EraCoded bead mixture. To each hybridization reaction, 0.5 L of 2 g/L streptavidin-R-phycoerythrin conjugate (Prozyme) plus 39.5 L of sheath fluid (Luminex Corp.) were added, and 65 L of the final reaction was injected into the Luminex 100 . pcr PCR primers were designed using Primer 3 (http:// www.broad.mit.edu/cgi-bin/primer/primer3_www.cgi) or Hyther (http://ozone2.chem.wayne.edu). Primer pairs were designed to flank the polymorphism(s) of interest and have a melting temperature of 53-57°C (see Table 2 in the online Data Supplement). A single iC was added to the 5Ј end of the PCR primers.