Fig. 1

Plate layouts and effect of residual trace P/GI on pH of conditioned medium. Ongoing cell cultures were designated according to their distance (in nearest whole-number well diameter units) from 1 well that briefly contained P/GI. Cells in the well adjacent to trace P/GI residue (i.e. 1 well away) are designated as W1, cells in the next well (2 wells away) as W2, and so on. Cells incubated on a separate 96-well plate without P/GI residue are referred to as “unexposed controls.” The layout depicted in A1 was used for morphological and gene expression data, and the layout in A2 was used for culture medium and gene expression data. B1) Appearance of culture medium 24 h after exposure to trace residual P/GI (P/GI placed into and immediately aspirated from an empty well). Representative plate from 3 repeated experiments. B2) Medium was sampled in duplicate from the cell culture wells and absorbance at 560 nm and 430 nm was measured, where higher ratios between them indicate a redder color and higher pH. For simplicity, values for the two adjacent wells labeled “W1” were averaged. Values show average 560/430 ratio ± standard deviation, which have been normalized so that the average absorbance in unexposed controls equals 1