Representation of amplicon melting temperature (Tm) values, in°C, plotted against Cp values (in cycles) obtained for field samples at the three sampled depths: Surface (orange), DCM (green) and DCM+40 (blue).

<p>For comparison, the graphs include the corresponding values from supplementary <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133207#pone.0133207.s007" target="_blank">S3 Table</a>. HL amplicons: <i>Prochlorococcus</i> strains MED4 (M4), MIT9515 (M5) and EQPAC1-C (EQ). LL amplicons: <i>Prochlorococcus</i> strains MIT9313 (M3), NATL2A (NA), and the <i>Synechococcus</i> strain WH7803 (WH).