Abstract Second-harmonic generation (SHG) is a nonlinear coherent scattering process that is sensitive to molecular structures in illuminated materials. We report SHG polarization measurement for the detection of protein conformational changes in solutions of macromolecular protein assemblies such as microtubules and protein crystals. The results illustrate the potential of this method for protein structural analysis in physiological solutions at room temperature without labelling.

Second harmonic generation polarization microscopy as a tool for protein structure analysis