Luminogenic and nonluminogenic multiplex assay

A method to detect live and/or dead cells in a sample, comprising:

• a) contacting a sample with a substrate for a first protease and a substrate for a second 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 permeant and the other substrate is substantially cell impermeant, and wherein if both reactions yield fluorogenic products, the fluorophores on the two substrates are spectrally distinct;
• 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.

A method to detect live cells in a sample, comprising:

• a) contacting a sample with a fluorogenic substantially cell permeable substrate for a protease associated with a proteasome, an aminopeptidase or a cathepsin;
• and
• b) detecting or determining fluorescence in the sample, thereby detecting or determining the number or presence of live cells in the sample.

A method to detect dead cells in a sample, comprising:

• a) contacting a sample with a fluorogenic or luminogenic cell impermeable substrate for a tripeptidyl peptidase, calpain or chymotrypsin;
• and
• b) detecting or determining fluorescence or luminescence in the sample, thereby detecting or determining the number or presence of dead cells in the sample.

A kit comprising:

• a composition comprising a first fluorogenic or luminogenic substantially cell impermeant substrate for a first protease and a second fluorogenic substantially cell permeable substrate for a second protease;
• and instructions for directing the user on the use of the composition to detect live and/or dead cells in a sample.

A kit comprising a composition comprising Ala-Ala-Phe-AMC, (Ala-Ala-Phe)2-R110, Ala-Ala-Phe-aminoluciferin, Gly-Phe-AFC, Gly-Phe-AMC, Gly-Gly-Leu-AMC, or any combination thereof.