There Are No Average Molecules | Exciting Instruments

For academics

There are no
average molecules

Single-molecule sensitivity for your lab - without changing your workflow.

The EI-FLEX system brings smFRET and FCS into any lab. Observe dynamic, in-solution molecular behaviour under physiologically relevant conditions - no dark room, no specialist expertise required.

Speak to an expert Discover EI-FLEX data

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The problem

You have powerful tools.
But key questions remain unanswered.

You already use world-class techniques - cryo-EM, X-ray crystallography, NMR, SPR. But they don't tell the full story.

Are bulk averaging and static techniques obscuring rare or transient intermediates?

How do molecules behave in real time, in solution?

Are you interested in binding mechanisms but feel like you're missing a piece of the puzzle?

For many labs, understanding dynamic behaviour in solution remains a critical gap - one that smFRET and FCS are uniquely placed to fill.

Where current approaches can be enhanced

The limitations holding your research back

Static structures miss dynamics

Structures provide snapshots - not motion. Intermediate states and transitions remain hidden, limiting functional understanding.

Solution Reveal dynamic, functional behaviour that static methods can't capture

Surface tethering introduces artefacts

Surface immobilisation can alter molecular behaviour - especially for proteins that don't behave well near hydrophobic surfaces.

Solution Keep molecules in solution and observe their native conformation

Complex workflows slow discovery

Answering one question often requires multiple techniques, long setup times, and specialised expertise.

Solution Label, dilute, and measure - often getting results in minutes, not days

Single-molecule access is limited

smFRET and FCS have been locked behind dedicated dark rooms, custom-built setups, and years of specialist expertise.

Solution Bring single-molecule capability to any lab bench - no dark room required

Introducing the EI-FLEX system

See the world as it really is,
in the detail that matters

The EI-FLEX system brings smFRET and FCS into any lab - revealing transient states, conformational dynamics, and binding affinities in real time. One simple, confocal benchtop instrument. No immobilisation. No specialist required. Just curiosity, a question, and a place on your bench.

In-solutionNo immobilisation - physiologically relevant conditions

Single-moleculeDetect rare states, transient intermediates, and conformational changes

Any labNo dark room or specialist expertise required

Drop-inComplements cryo-EM, NMR, X-ray crystallography and more

Discover the EI-FLEX system

What you can do

Purpose-built for the questions that matter

Each capability is designed to close the gaps that existing methods leave open.

Capture conformational dynamics and nanoscale distances

smFRET reveals transient states and heterogeneous populations in real time - bridging the gap between high-resolution structures and functional dynamics.

smFRET

Measure diffusion dynamics and binding affinity

FCS quantifies binding affinities, absolute concentration, hydrodynamic size, and fluorophore brightness - all with single-molecule sensitivity.

FCS - FCCS

Measure molecules in their native state

No immobilisation. No surface tethering. Observe native conformation under physiologically relevant conditions you can trust.

In-solution - Native conditions

Complement your existing techniques

EI-FLEX system users have combined smFRET and FCS with X-ray crystallography, NMR, TIRF-FRET, MST, SAXS and more - expanding insight, not replacing tools.

Highly complementary

Make advanced insight accessible

PhotonFlux and PhotonFit software distil biophysics expertise into an intuitive interface - guided acquisition, real-time visualisation, and publication-ready figures.

Designed for every lab

Trusted by leading researchers

Used across structural biology, biophysics,
and mechanistic biochemistry

"What sets the EI-FLEX system apart is its versatility - it's our go-to for probing kinetics and conformational changes that the other systems can't resolve. This opens up a range of research for us that was previously impossible."

Professor Edwin Antony - Saint Louis University

Built for your research questions

The answers your current methods can't give you

These are the questions researchers are now answering with the EI-FLEX system.

What conformational states exist between known structures?

How do biomolecules behave in real time, in solution?

How does the binding of biomolecules drive biological function?

Are rare or transient intermediates being obscured by bulk averaging?

Get started

Bring single-molecule power
to your bench

Find out how the EI-FLEX system can answer the questions your current toolkit can't - no dark room, no specialist expertise required.

Speak to an expert Learn more about the EI-FLEX system

There are noaverage molecules

You have powerful tools.But key questions remain unanswered.