Raw ddPCR abundance of UCYN-A2 and UCYN-A1 from DY167

Abundances of B. bigelowii/UCYN-A1 and B. bigelowii//UCYN-A2/A3/A4 were estimated from 11 surface water filtered seawater samples (< 3m, Sterivex 0.22 µm)using digital droplet PCR (ddPCR) using the assays originally developed for Taqman® quantitative PCR by Church et al., (2005) and Thompson et al., (2014), respectively. All reaction conditions, thermocycling parameters, thresholding and calculations of the limit of detection and limit of quantitation are described in Gradoville et al., (2020). Note that the abundances determined using the UCYN-A2/A3/A4 assay likely represent both UCYN-A2 and UCYN-A4, both of which were recovered via nifH amplicon HTS.