Antifoam addition can affect both retained and secreted GFP. The amount of GFP retained in the cell was analyzed by flow cytometry (white bars), while that secreted into the culture medium was analyzed by fluorimetry (black bars). In order to compare these two different data sets, each was normalized to its respective 0% antifoam control, which was consequently set to 1. The values shown are for determinations at 48 h (n = 3). The significance of the changes in retained (white bars) and/or secreted (black bars) GFP compared to the respective 0% antifoam control was analyzed by a one-way ANOVA (P < 0.0001) and a Dunnett's multiple comparison test where * = P ≤ 0.05 and ** = P ≤ 0.01.