Because each EraCode should be specific only for its complementary tag, only the bead that contains the specific EraCode should report a high MFI. Results show that for the correct complementary code, specific signal was between 2130 and 4357 MFI, with a mean (SD) MFI of 3040 (532; see Table 4 in the online Supplemental Data). Signals generated on microspheres that contained Era-Codes that were not completely complementary varied from 0 to 320 MFI with a mean (SD) MFI of 92 (28) . This set gave signal-to-noise ratios that ranged from 32:1 and 10:1 for the worst cases (i.e., where the specific signal was compared with the nonspecific signal from the microsphere presenting the highest noise). To our understanding, there have been no reports of a genetic-based molecular recognition system that was successfully implemented at room temperature without washing. mutation analysis using the manual cf multicode system PCR amplicons were generated for 17 regions within the CFTR gene, and 63 tagged extenders were used to analyze 27 mutations and 4 reflex targets. To improve the robustness of the overall results, the test was divided into four reactions with one additional test targeting the 5T7T9T reflex target. Two additional targets were included late in the development phase to include 394delTT and 3199del6. The test was transferred to the Wisconsin State Laboratory of Hygiene, where newborn CFTR genetic screening has been ongoing since 1994 and multimutation testing used since 2002.