Hyperspectral fluorescence Imaging: the potential of cryogenic detectors
David Ray
Chief Technology Officer BioAstral Limited
What does BioAstral have to offer the stem cell research community?
We have taken detector technology developed by ESA for X-ray astronomy and deployed it down the microscope to image fluorescence from bioassay
This capability is based on superconducting tunnelling junction (STJ) devices
Initial results using specialised kit at ESTEC, based on single pixel tantalum detectors, took us
by surprise
Photon detection across the visible spectrum from UV to IR
Two to three orders of magnitude improved sensitivity over conventional PMT or CCD detectors
Essentially no background noise
We measure the energy of photons directly, without the need to infer colour by use of filters
This adds up to the potential for sensitive and true hyperspectral imaging across the optical spectrum and into
the infra red
This might have been a curiosity restricted to specialist cryogenic labs
But for the quite independent development of commercially available user-friendly cryogen-free coolers capable of
operating at extended periods at milliKelvin temperatures
Here we had the potential to take STJ detectors and operate them in a biology lab
And this has been the focus of BioAstral efforts to date: to take STJs and get them to operate routinely in the new coolers
Scanner Process
Excitation
FluorescentBiomedical
Sample
CoolerSTJ
Light capture
Data acquisition
Data analysis
1
2
3
Instrument control
4
We still have some technical problems to resolve before our STJs work as well in the Heliox cooler as they do in
ESA’s helium dilution refrigerators
But we have identified solutions to these problems and we have the resources in place to implement these
Our next step will be to refine the benefits of HPD for live cell research
The ability to look at two, three perhaps more colours simultaneously without problems of photo-bleaching
The use of lower excitation energies
The use of fluors better suited to maintaining cell viability
Possibly even the use of auto-fluorescence to selectively characterise cell biomarkers
True multicolour photon imaging
Potentially transformative in terms of biology and life sciences research
Enabling diagnostics for personalised medicine
Disruptive of current markets