Patent ID: 7527924

Claim:
A method for quantitating intact viable cells compared to total cells in a sample, comprising: i. providing a sample containing total cells, ii. measuring the native UV fluorescence of said total cells, wherein said native UV fluorescence represents the number of total cells in the sample, iii. contacting said sample containing said total cells with molecule or dye that is detectably altered by enzymatic activity of a viable cell; iv. measuring a total amount of fluorescence of enzymatically altered molecule or dye, wherein said total amount of fluorescence of enzymatically altered molecule or dye represents the number of viable cells in the population, and wherein said enzymatically altered dye or molecule comprises fluorescein diacetate or OREGON GREEN™ (2′,7′difluorofluorescein); v. correlating the UV fluorescence measured in step (ii) with a total cell count correlation measurement, that correlates values of native UV fluorescence with total cells/ml, thereby determining the number of total cells in the sample; and vi. correlating the total amount of fluorescence of enzymatically altered molecule or dye measured in step (iv) with a viable cell count correlation measurement, that correlates values of fluorescence of the enzymatically altered molecule or dye with total viable cells/ml, thereby determining the number of total viable cells in the sample; thereby quantitating viable cells compared to total cells in said sample and wherein said measuring of fluorescence in steps (ii) and (iv) is performed by a fluorometer.