Fig. 3

Proportions of operational taxonomic units (OTUs) in four bacterial mock communities using two DNA extraction methods, with triplicate testing. A gradient scale is used to represent the proportions of the 100 most abundant OTUs detected across the bacterial mock community controls. OTU and genus-level classifications are provided on the left and right side of the figure, respectively. OTUs expected in each of the four bacterial mock communities are shown using green squares. Red squares denote OTUs not expected in the four bacterial mock communities (“background OTUs”). The bacterial mock communities (Primestore vs STGG), their biomass (high versus low) and the DNA extraction methods used are denoted at the top of each heatmap