Fig. 4

Relationship between mean relative abundance estimates and GC percentage for datasets 1 and 4. There is a significant negative linear relationship for both the MiSeq (p = 0.002, n = 96, Additional file 4: Table S3) and HiSeq (p = 0.012, n = 24, Additional file 7: Table S6) data. Estimates drop by 0.18 and 0.16% for each 1% increase in GC content for the MiSeq and HiSeq estimates, respectively