Work performed over the 26 months of Project SMILE (01Jan17 to 28Feb19)
Project SMILE sought to develop an existing prototype of a laboratory-scale soft x-ray microscope into a Pilot system that would be sufficiently reliable to be used for customer evaluation and, in so doing, to begin the process of product commercialisation. SiriusXT had been founded one year prior to the start of Project SMILE with the goal of designing, building and commercialising a laboratory scale Soft X-ray Microscope. During the one-year period prior to the start of Project SMILE SiriusXT developed and built the prototype microscope. The goals of project SMILE were, therefore, 100% aligned with SiriusXT's business strategy.
The first major task in the project was to re-engineer the prototype design so that it was mechanically capable of reliably producing high resolution, high contrast, sample images. The goal was to start first with 2D images of 'dry' (non-biological) samples that could be imaged at room temperature and then to progress to 2D images of cryo-frozen biological samples. Tomograms (3D images) would then be produced by combining a series of 2D images of the sample, taken as the sample was progressively turned around a axis of rotation.
The work required to re-engineer the prototype microscope into a reliable, precision, imaging instrument proved to be much greater than had been anticipated as it required multiple iterations of module redesign. The delays in achieving this goal had a ripple-on effect on the other project goals since most of these required a fully functioning microscope to be available.
Notwithstanding this, the progress made through the project was very significant and the images and performance produced demonstrated an imaging resolution comparable with the synchrotron-based microscopes. Furthermore, SiriusXT has been successful in raising additional funding from institutional investors to continue the product development and to complete all the project goals.
The results obtained from the soft x-ray source testing has been shared with the operators of the European synchrotrons and they have been very supportive with advice on how to integrate the microscope optics for best imaging performance. SiriusXT personnel have also worked closely with operators of cryo-imaging laboratories, who have developed expertise in cryo- cell preparation for electron microscopy applications as well as for soft x-ray imaging at the synchrotron beamlines. By October, 2017, we have the capability to screen cryo-prepared grids, populated with cells, on a fluorescence microscope and to then transfer the frozen cells in a custom-designed transfer box to the cryo stage of the microscope. The results of this cryo-cell handling work has been described and published on the SiriusXT’s LinkedIn page and on the Cryo Microscopy LinkedIn Group page, which has over 1,000 members interested in cryo-cell microscopy.