Correlative Super-Resolution Fluorescence Imaging and Atomic Force Microscopy for the Characterization of Biological Samples.

Recent advances in imaging tools have greatly improved our ability to analyze the structure and molecular components of a wide range of biological systems at the nanoscale. High resolution imaging can be performed with a handful of techniques, each of them revealing particular features of the sample. A more comprehensive picture of a biological system can be achieved by combining the information provided by complementary imaging methods. Specifically, the correlation between super-resolution fluorescence imaging and atomic force microscopy (AFM) provides high resolution topography as well as specific chemical information, the latter with a spatial resolution that approaches that of AFM. We present a detailed protocol and discuss the requirements and challenges in terms of sample preparation, instrumentation, and image alignment to combine these two powerful techniques. This hybrid nanoscale imaging tool has the potential to provide robust validation for super-resolution methods as well as new insight into biological samples.