This paper presents an interactive audio-haptic human-computer interface for controlling an atomic force microscope (AFM) in force spectroscopy experiments on single molecules. The sensor data used are proportional to the force that is applied to a single molecule. These forces are measured in real-time by using the reflection of a laser beam from a cantilever. We present a system that involves (a) a visual display of the data (b) a force-feedback joystick for navigating the sample and providing a tactile feedback of the forces, and (c) an auditory display to monitor the measured data while interactively moving the sample. The sonification we have developed integrates information at various levels of detail, including audifications of the high-frequency cantilever movement, and an auditory stream that communicates the instantaneous deviation of forces between the approach and retract phase of the sample. The sonification design and offline-computed sonifications will be presented and discussed. We further report on our first experiences with this interactive multi-modal control interface for manipulation of individual DNA molecules.