Application of a fluorescent redox dye for enumeration of metabolically active bacteria on albumin-coated titanium surfaces.

A bacterial staining method using fluorescent redox dye 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) is described for quantifying actively respiring bacteria that adhere to commercially pure titanium surfaces coated with cross-linked albumin. This has not been possible to date using ordinary DNA stains such as propidium iodide (PI) or Hoechst, both of which produce a very bright background. With this technique, it was demonstrated that the cross-linked albumin inhibited the adherence of Staphylococcus aureus and Staph. epidermidis to the titanium surface.