As a substitute to istope labelling, chemiluminescence has become the most significant labelling technique in the detection of faint signals in Southern-, Northern- and Western Blot detection. Most important chemiluminescence assays are luminol- based with horse radish peroxidase (HRP) as catalyzing enzyme or dioxethane based with alkaline phosphatase (AP) as labelling enzyme. The cooled CCD-camera systems such as our new Stella provide excellent detection results for qualitative and quantitative analysis.