Xiyan Li Author Answered Sep 16, 2011
Department of Genetics, Stanford University, USA
Since cell lysis is not involved in your experiment, you can use your sample as cell lysate in most assays developed for cells. Very general methods can also be found in literature or on the web, and commercial fluorescence-based reagents from several vendors such as Promega, Pierce, and others. Search for "beta-galactosidase fluorescence" will yield enough information.