Cell size explains variation in the cell density - cell count relationship
We expected cell size to inversely predict the steepness of slopes extracted from cell density - cell count regressions, because a given optical density may result in fewer cell counts if cells are on average larger. However, we found the opposite: the steepness of strain-specific slopes extracted from cell density - cell count regressions increased slightly with increasing strain cell size (R2 = 0.24;p = 0.0223; Figure 4).