Well, try using Digoxigenin-labeled probes. Boehringer offer labeling kits. They are then developed with a flourescent marker and films. Works nicely. Volker -- Dr. Volker Blaschke Dept. of Biochemistry Georg-August-University, Goettingen, Germany CompuServe: 74740,50 Email: vblasch at gwdg.de Tel: xx49 551 39 5959 / 5978 Fax: /5960