Quantitative assessment of labeling probes for super-resolution microscopy using designer DNA nanostructures.

Improving labeling probes for state-of-the-art super-resolution microscopy is becoming of major importance. However, there is currently a lack of tools to quantitatively evaluate probe performance regarding efficiency, precision, and achievable resolution in an unbiased yet modular fashion. Here, we introduce designer DNA origami structures combined with DNA-PAINT to overcome this issue and evaluate labeling efficiency, precision, and quantification using antibodies and nanobodies as exemplary labeling probes. While current assessment of binders is mostly qualitative, e.g. based on an expected staining pattern, we here present a quantitative analysis platform of the antigen labeling efficiency and achievable resolution, allowing researchers to choose the best performing binder. The platform can furthermore be readily adapted for discovery and precise quantification of a large variety of additional labeling probes.