# Quantitative Stimulated Emission Depletion (STED) Microscopy with DNA-Fluorophore Labels

## TL;DR

This paper introduces a new method for counting molecules using STED microscopy with DNA-fluorophore labels, enabling precise imaging at the single-protein level.

## Contribution

A new DNA-fluorophore labeling method for quantitative STED microscopy with molecule counting capability.

## Key findings

- Accurate molecule counting was demonstrated on DNA origami structures.
- EGF receptor monomers and dimers were visualized and quantified in cells.
- The method is robust, fast, and easy to implement for single-protein resolution.

## Abstract

Stimulated emission depletion (STED) microscopy enables
super-resolution
imaging of complex biological samples in 3D, in large volumes, and
live. However, molecular quantification with STED has remained underexplored.
Here, we present a straightforward approach for quantitative STED
that enables molecule counting. For this purpose, we designed DNA-fluorophore
labels that enable signal amplification and allow for reliable intensity-based
quantitative imaging. We demonstrate accurate molecule counting on
DNA origami. Furthermore, we visualized and quantified EGF receptor
monomers and dimers in cells. In summary, we introduce a robust, fast,
and easy-to-implement tool for quantitative STED microscopy with single-protein
resolution.