Figure 6.

Northern blot analysis to determine the expression of S. metallicus copA1 (a) and copA2 (b) putative genes in response to various metals. S. metallicus total RNA was extracted from cultures grown either in the absence (control) or the presence of CuSO₄ (50 mM), Ag₂SO₄ (0.08 mM), NiSO₄ (15 mM), ZnSO₄ (50 mM), and CdSO₄ (2 mM). P³²-radioactivelly labelled DNA fragments annealing to copA1 and copA2 sequences, respectively, were used as probes. (c) shows rRNAs as total RNA loading control.