Fig (2) NKH 477 stimulated β-lactamase activity in CRE-bla CHO cells in 1536-well format. (A). Time course of NKH 477 stimulated β-lactamase activity in CRE-bla CHO cells in 1536-well format. (B). DMSO effect on the NKH 477 stimulated β-lactamase activity assay.