The Fluidity One-W (coming soon)

High sensitivity in-solution analysis of protein size and protein interaction kinetics

  • Measure with confidence

    Analysis is performed in solution, meaning it is more physiological and less prone to artefacts caused by surface functionalization or non-specific matrix interactions.

  • Sizing in complex solutions

    Size fluorescently labelled recombinant proteins expressed in cell lysates, without the need for sample separation using matrices or columns.

  • Size multiple species simultaneously

    Monitor hydrodynamic radius changes of multiple components of a complex as it forms using the multi-wavelength capability of the Fluidity One-W.

  • Rapid results with less

    Requiring just 5 μL of sample, and with measurements in as little as 8 minutes, the Fluidity One-W allows you to run more experiments and collect more data

  • Reliable data

    Disposable chips eliminate risk of contamination and mean there’s no need for time-consuming wash cycles.

  • Go beyond protein

    Fluorescent detection allows you to apply microfluidic diffusional sizing to any fluorescent labelled particle – such as DNA, lipids, sugars or even polymers.


The fluorescence detection capabilities of the Fluidity One-W mean you can measure single protein species in complexes to look at protein-protein interactions, or go beyond proteins to study any fluorescent labelled particle – such as DNA, lipids, sugars or even polymers.

Protein-protein interaction analysis

Study the formation of protein complexes by monitoring changes in hydrodynamic radius of your protein of interest as its binding partner is introduced

Protein-DNA interaction analysis

Quantitative analysis of size changes following the introduction of putative DNA binding proteins, without the requirement for radiolabelled oligonucleotides.

How does the Fluidity One-W work?

The rate of diffusion of a particle is proportional to its hydrodynamic radius – a relationship that is as described by the Stokes-Einstein equation. The Fluidity One-W exploits this observation by measuring the rate of diffusion of proteins under steady state laminar flow.

As with the Fluidity One, when a protein sample and analyte solution are run as adjacent (non-mixing) streams, the only way protein can migrate into the analyte stream is by diffusion – at a rate that is proportionate to its size.

However, unlike the Fluidity One, the One-W is capable of measuring pre-labelled, fluorescent proteins, and in this manner can size specific proteins in complex mixtures. And so following diffusional measurement, the streams are split and fluorescence intensity is then measured in both streams, the ratio of which is used to determine the diffusion coefficient, and consequently the hydrodynamic radius. 

Would you like to be an early adopter?

The Fluidity One-W is currently in development, and we’re enrolling early access partners to help us define the specification of the instrument based on their applications. If you'd like to learn more and potentially participate then get in touch

Fluidic Analytics is changing how proteins are characterised

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