Built to unlock the power of single-molecule fluorescence spectroscopy

Find out more about the EI-FLEX system Hardware

The EI-FLEX System

The EI-FLEX system is an easy-to-use, cost-effective, benchtop instrument capable of two-colour, single-molecule fluorescence detection in solution, with two key modes:

Single-molecule Forster Resonance Energy Transfer (smFRET Mode).

Fluorescence Correlation Spectroscopy (FCS Mode)

Equipped with advanced software to provide real-time data visualisations and complex data analysis at the push of a button. The EI-FLEX is an affordable platform technology for making discoveries in biophysics, life sciences, drug development and medical diagnostics.

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Simplifying Single Molecule Spectroscopy

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Understand Every Molecule

Go beyond the capabilities of traditional assay methods and plate readers with single-molecule sensitivity.

Make precise distance measurements in the 3- 10 nm range using our smRULER calibration features.

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From Discoveries to Diagnostics

Perform accurate studies of chemical, biological and physical processes at low (picomolar) concentrations.

Measure the interactions, complexing and kinetics of DNA, proteins, antibodies, enzymes and kinases.

Interface built to simplify
An Interface Built to Simplify

Easy-to-use software with real-time graphing and in-built analysis tools help you accelerate the assay validation process.

Cloud connectivity makes your collaborations agile, enabling results sharing within research groups.

About Exciting Instruments

Exciting Instruments Limited is a joint venture, built in Sheffield, stemming from the software brains of Bulldozer Limited and the single-molecule expertise of Dr Timothy Craggs. We are a true partnership of science and software, with a mission to help you simplify the process of making discoveries in biophysics, life sciences, drug discovery and medical diagnostics, through the use of cloud connectivity and real-time data visualisation. 

Our Senior Management Team

Dr Timothy Craggs

Dr Timothy Craggs

Founder and CSO

Tim is an internationally renowned expert in the development and application of single-molecule FRET methods and in the detailed biophysical characterisation of protein folding, and protein-nucleic acid interactions. As a champion for open science and accessibility, Tim founded Exciting Instruments in order to bring his team's developments in single-molecule spectroscopy to the broadest possible user base.

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Robert Bell


Rob leads software development, which forms the backbone of each of Exciting Instruments technology offerings. As a Director of Bulldozer Limited, and a lead software engineer at Razor Limited, Rob has built an extensive portfolio of successful grass-roots technology companies that have generated fast growth and unrivalled software functionality through his skill at taking ideas and making them a reality.

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Chris Sellars


Chris Sellars is a specialist in providing intelligent, proactive and candid advice to technology companies, and brings a pragmatic approach when making the Exciting Instruments vision a reality. Chris’ background in corporate finance provides the solid foundation which continues to drive Exciting Instruments expansion.