# Vortex‐Generated Microdroplets Enable Simple, Rapid, and Low‐Volume Measurement of Condensate Volume and Concentration

## TL;DR

A new method uses microdroplets to quickly and accurately measure the volume and concentration of biomolecular condensates with minimal sample and cost.

## Contribution

A vortex-assisted microdroplet method enables rapid, low-volume, and calibration-free quantification of condensate properties.

## Key findings

- The method reduces processing time by over tenfold and sample volume by two orders of magnitude.
- It maintains accuracy comparable to conventional methods while enabling in situ quantification.
- The technique can detect subtle changes in condensate properties under varying environmental conditions.

## Abstract

Biomolecular condensates are increasingly recognized for their crucial roles in intracellular organization and the origin of life. Despite their growing importance, efficiently and accurately quantifying condensate volume and concentration remains challenging, hindering the understanding of their properties and functions. Conventional spectroscopy‐based methods for measuring condensate concentration in bulk systems have practical limitations; for example, they require laborious calibration and preparation procedures, large sample volumes, and in vitro analysis. Here, we introduce a microdroplet‐based method that leverages a simple and rapid vortex‐assisted emulsification approach to encapsulate condensates within microdroplets. By determining the microdroplet‐to‐condensate size ratio and partition coefficient in situ, this method enables rapid and calibration‐free quantification of molecular concentrations within condensates. Notably, it reduces processing time by more than tenfold and reduces sample volume and material cost by over two orders of magnitude, while maintaining accuracy comparable to conventional methods. Moreover, this method can precisely quantify subtle variations in condensate volume and concentration under changing environmental conditions, such as salt concentration and stoichiometries. The microdroplet‐based method is anticipated to find broad applicability in fields where precise, efficient, and in situ quantification of condensate volume and concentration is critical, particularly when sample volumes are limited or environmental conditions are dynamic.

This work leverages vortex‐generated microdroplets to encapsulate condensates and quantify their volumes and concentrations. Compared to conventional bulk methods, the technique substantially reduces sample volume, cost, and processing time. Its broad utility sheds light on a wide range of applications, particularly those that require high‐throughput and cost‐effective characterization of condensate properties.