Patent ID: 7026111
Filing Date: 2006-04-11
Classification: C12Q

Abstract:
1. A method for assaying a metabolically active whole cell for the presence or activity of an enzyme, comprising the steps: (a) providing a sample comprising an intact metabolically active whole cell in medium; and (b) providing a mixture composition comprising a substrate of said enzyme or an analyte compound and an agent that enhances/uptake of said substrate or analyte compound; and (c) adding said mixture composition to said sample, wherein said mixture composition subsides within said medium of said sample to form a layer of said mixture composition over said intact metabolically active whole cell, wherein said layer is not homogeneously mixed with said medium of said sample; and (d) assaying said sample for any change in concentration of said substrate or analyte compound or of a product formed via action of said enzyme on said substrate or analyte, wherein said cell remains intact at the conclusion of said assay, wherein a change in said concentration is indicative of the presence or activity of said enzyme in said metabolically active whole cell; and wherein said agent that enhances uptake of said substrate or analyte is selected from the group consisting of glycerol, dimethyl sulfoxide (DMSO), trehalose, glutamate, betaine, ethylene glycol, threitol, ribose, and trimethylamine N-oxide, with the proviso that when said agent is dimethyl sulfoxide (DMSO), said agent will be present at a concentration of between about 20% and about 60% (v/v).