The long-term objectives of the proposed research are to further develop the Differential viscometer (DV) and to demonstrate the potential utility of this new instrument for the solution of significant biomedical problems. Specifically in Phase I it is intended to accomplish the following: (1) Show that the speed and sensitivity of the DV makes it useful in a screening program to detect drugs and other compounds that intercalate with DNA. (2) Couple a simple flow injection analysis system to the DV for an alternative approach to the DNA-drug testing. (3) Develop a modified DV for use as an on-line detector for GPC/HPLC. These goals have considerable potential for producing a line of commercial instruments that interface with a wide range of techniques in biochemistry.