The InflA probe was tested against 70 nt target molecules with 3, 5, 7, 9, 11, 12, 13, 14, 15, 16 and 21 point mutations (pm) and 21 grouped mutations (gm) (Figure 2A -D; nt sequences of probes and targets can be found in Supplementary Tables S1A and B). The positions of the pm were based on the variations found by comparing H3N2, H5N1 and H1N1 viruses. Two targets had the same number of mutations, but different distributions: the 21 pm target had 21 evenly distributed pm, and the 21-gm target had seven groups of three mutations interspersed by 5 to 7 conserved nt. The InflA probe, coupled to Luminex microspheres, was allowed to hybridize with one of the biotinylated ssDNA targets in 3 M TMAC at two different temperatures: 45 C ( Figure 2A ) and 55 C ( Figure 2B ). The hybridization, given as MFI, was analyzed in the Luminex flow meter.