Figure 4
Pairwise variations (Vn/n+1) for all the samples (biofilms and planktonic cells) and biofilms and planktonic cells separately. Pairwise variation between every combination of sequential normalization factors were calculated to determine the minimum number of housekeeping genes required for accurate normalization in the different samples. The cut-off value, below which the inclusion of an additional housekeeping gene does not result in a significant improvement of normalization, was set at 0.15.