Patent ID: 7553632
Filing Date: 2009-06-30
Classification: C12Q

Abstract:
1. A method to detect live and/or dead cells in a sample, comprising: a) contacting a sample comprising cells suspected of having one or more proteases with a peptide substrate for a first nonsecreted protease and a peptide substrate for a second nonsecreted protease, wherein a reaction with one of the substrates mediated by one of the proteases yields a fluorogenic product and a reaction with the other substrate mediated by the other protease yields a luminogenic or a fluorogenic product, wherein one of the substrates is substantially cell membrane permeant and the other substrate is substantially cell membrane impermeant, wherein if both reactions yield fluorogenic products, the fluorophores on the two substrates are spectrally distinct, and wherein the substantially cell membrane permeant substrate is capable of detecting or determining the number or presence of live cells in the sample and the substantially cell membrane impermeant substrate is capable of detecting or determining the number or presence of dead cells in the sample as a result of protease activity released into the extracellular environment due to loss of membrane integrity; and b) detecting or determining fluorescence and/or luminescence in the sample, thereby detecting or determining the number or presence of live and/or dead cells in the sample.