Joan, The Y-DNA is passed from father to son, to son, forever. A test for the French surname requires a male who has the surname of French. A test for a Farnsworth, requires a male who has that surname. The only time the two would match would be if an adoption had occurred in one of the lines that changed their surname. Julia In a message dated 10/29/2006 2:13:29 AM Central Standard Time, joanl@earthlink.net writes: Question: If I pay to do a DNA test on my Farnsworth side of the family, can those results also be used for the French project ? Or must I pay and do another test ?? Joan Lutz joanl@earthlink.net