I want to do an assay to see, if an ordered enzyme is active or not. It's a glucosyltransferase from S. mutans which hydrolyses sucrose into fructose and glucose. It then connects the glucose-monomers to dextran. Our idea is to detect the free fructose. There are many tests for this, for example the Fehling-Test or the Tollen-Test. The trouble is, that they have to be heated on a waterbath - I think that's very suitable for microwell-plates. Maybe someone here has a better idea how to measure the enzyme's activity?