Special CPM Seminar

Optical tweezers combined with AFM -
Investigating cell mechanics and single molecules on multiple scales

Florian Kumpfe

JPK Instruments

While optical tweezers (OT) and AFM have a successful history in biophysical research, setups that combine the advantages of both are rarely found. This can be mainly ascribed to the technical challenges arising from the complexity of the individual methods. In some studies, OT and AFM have been used subsequently on the same type of sample to perform force spectroscopy at different scales. Truly simultaneous optical trapping and AFM measurements, however, have not been available.

Here we present a novel OT-AFM setup that combines high precision optical manipulation, camera-based force detection and the full spectrum of AFM methods on the same sample at the same time. This opens up new approaches to complex experimental designs that are not accessible by AFM or OT alone. It was used in immune-biology experiments to characterize the influence of dendritic cell + T-cell interaction on cellular adhesion. In addition to results from these measurements, we will introduce further application examples from the field of single-molecule interactions, cell mechanics and medicine.