FIGURE 1.

Fluorescence images (SYBR gold 497/537 nm) showing immediate DNA damage and plots showing increased DNA fragmentation after short (F) and long (G) exposure to 1 mM and 4 mM 2,4-D, respectively. Escherichia coli exposed to 1 mM 2,4-D showed increased DNA damage measured as a function of increased DNA spreading after 5 s (B), increasing further after 10 (C), 30 (D), and 60 s (E) compared to the representative formula control (A). Arrows highlight halos around the cells. Formula sample contained all the ingredients of the formulation (refer to section “Materials and Methods”) without 2,4-D and the sample control contained deionized water. Cells also showed significantly increased DNA damage after longer exposures to 4 mM 2,4-D (n = 100). H₂O₂ and high temperature were used as positive controls. Error bars indicate standard deviation.