Pros and cons of using resazurin staining for quantification of viable Staphylococcus aureus biofilms in a screening assay.

Staining of Staphylococcus aureus biofilms with 20 microM resazurin during 20 min was shown to provide a good screening assay in 96-well micro titer plates. However, data quality was found to be dependent on the staining duration and biofilm concentration. Also, the inadequacy of using resazurin calibration curves with planktonic cells to estimate S. aureus biofilm concentrations was demonstrated.