Extended Data Fig. 2 |. Intracellular metal quantification using ICP-MS.

(a) The intracellular concentrations of Mg, (b) Co, (c) Cu, and (d) Zn were monitored using ICP-MS for four hours after 1 mM FeSO₄ was added to cultures of C. difficile WT, ΔfezB, and ΔfezB pJS116-fezB cells grown in BHIS amended with 100 μM dipyridyl. The data are expressed as parts per million (ppm) per gram cell pellet. Experiments were conducted two times independently with similar results. Data are presented as mean ± SEM (n = 6). No significant differences were observed between strains at each timepoint based on two-tailed t tests.