Patent ID: 8993259
Filing Date: 2015-03-31
Classification: C12Q,G01N

Abstract:
1. A method of detecting viable cells in a cell sample, the method comprising the steps of: (a) exposing cells in the cell sample to (i) a membrane permeable nucleic acid binding fluorescent dye under conditions that permit the fluorescent dye to permeate both viable and non-viable cells, and (ii) a membrane impermeable nucleic acid binding fluorescence quencher capable of quenching fluorescence produced by the fluorescent dye under conditions to permit the quencher to selectively permeate non-viable cells but not viable cells, wherein the fluorescent dye and the fluorescence quencher bind to nucleic acid within a non-viable cell to form a complex that is substantially non-fluorescent; (b) after step (a), exposing the cells to light having a wavelength capable of exciting the fluorescent dye to produce a fluorescent emission; and (c) detecting the fluorescent emission, if any, from the cells, wherein the fluorescent dye within the non-viable cells emits substantially less fluorescence than the fluorescent dye within the viable cells, thereby to detect the viable cells in the cell sample, and wherein the cells are microorganisms.