1. Hyperspectral fluorescence Imaging: the potential of cryogenic detectors David Ray Chief Technology Officer BioAstral Limited

2. 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

3. 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

4. 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

5. Scanner Process Excitation Fluorescent Biomedical Sample Cooler STJ Light capture Data acquisition Data analysis 1 2 3 Instrument control 4

6. 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

7. 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

8. True multicolour photon imaging Potentially transformative in terms of biology and life sciences research Enabling diagnostics for personalised medicine Disruptive of current markets