If your problem is RNA/DNA duplex, then why don't you get rid of your RNA by Hydrolyzing it. Use NaOH ...etc to get rid of RNA and if that's your problem then you should be able to see your stuff on the gel. I hope this helps, Cheers. Shahram Mori Program in Molecular Biology Dept. of Chemistry and Biochemistry Box 3C NMSU, Las Cruces NM 88003 _/\_ _\ /_ \_ _/ ||