One of the limitations of this study is that we did not save the actual strains from the 3 influenza seasons studied, since the laboratory was no longer performing viral cultures. However, the H3N2 strains analyzed for the matrix gene in the 2012–2013 and 2014–2015 seasons are generally considered representative of the sequence variation observed in the matrix genes, and the H1N1 isolate was an environmental isolate obtained on the University of Florida campus near the peak of the 2013–2014 season. Likewise, sequence analysis of HA sequences available from GenBank for representative H3N2 strains showed no changes in the number and location of mismatches in the GenMark assay between the 2012–2013 and 2014–2015 seasons. Another issue, although not strictly a limitation of the study, is that the GenMark assay is more complex than traditional TaqMan assays, in that after the PCR product is produced, it is captured on a solid phase where a 4th probe that carries a ferrocene label is required to bind to permit detection of an electrical signal. Although a positive assay is reported from 3.0 to >300 nAMPs, in our experience the actual linear range is only about 10–30 fold, which is very narrow compared with the generally observed 5 logs of linearity for a typical TaqMan assay.