MULTIPURPOSE HIGH-SENSITIVITY LUMINESCENCE ANALYZER (LUANA) - USE IN GEL-ELECTROPHORESIS

Many applications in molecular biology require the rapid and high-sens itivity detection of biological macromolecules. Here we describe a lum inescence analyzer (LUANA), featuring xenon lamp-based illumination an d a cooled CCD camera as detector Luminescent samples (gels, membranes or microplates) are placed in a light-tight chamber and computer soft ware is used to control the camera and to display and analyze the imag es. LUANA can be used with a broad spectrum of excitation and emission wavelengths (200-1000 nm), allowing a choice of many fluorescent dyes and facilitating multicolor imaging. We show that LUANA is readily ap plicable to gel electrophoresis and highly sensitive; on gels we could detect <100 fg of Cy5(TM)-labeled protein and 0.1 ng of plasmid DNA l abeled with a fluorescent intercalator. We observed a linear response for sample concentrations differing by two orders of magnitude using a single acquisition rime. This range could be further extended by usin g different acquisition times. We haw also used LUANA in two-color ima ging of DNA and for screening of antigen-antibody and peptide-protein complexes by gel bandshift.