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.