I have used Pfu with great success in amplifying segments up to 2.5 kb with no loss of fidelity. This also worked with high G-C regions (80%) Tony Sanchez University of Florida Dept. Ophthalmology 1600 SW Archer Road JHMHC #100284 ARB R4-146 Gainesville, FL 32610 Phone (904)392-2720 Fax (904)392-7839 e-mail = tsanchez at eye1.eye.ufl.edu