Waigh's group applies advanced optical and biophysical techniques to study complex biological fluids and single molecules. Research directions: (1) Microrheology — diffusing wave spectroscopy and optical trapping microrheology to measure viscoelastic properties of biopolymer networks and cytoplasm; (2) Antibody / protein dynamics — tracking single-molecule diffusion of antibodies and receptors in complex biological environments using fluorescence; (3) Non-linear flows of antibodies — studying anomalous diffusion and aggregation of therapeutic antibodies; (4) Neutron and X-ray scattering — structural characterization of complex biofluids at PSI facilities. Bridges soft matter physics and single-molecule biosensing.