Tiffany Sessions vanished in Gainsville while jogging in February 1989.
Patrick Sessions says investigators have told him the FBI Office in Jacksonville is testing a piece of material that may have belonged to his daughter, Tiffany.
A jailed informant told police where to find the evidence two years ago. The material will be compared with DNA samples from Tiffany Session's parents.
Results from the DNA testing are expected within a few weeks.