Microscopes

Tender description

A number of PIs in the College are interested in imaging the dynamics of circulating immune, stem and tumour cells within microvessels in real-time, primarily in vivo, but also in explanted living tissue. To study this, we are using tissue sections which means dynamic cellular events are not being monitored in real-life in physiological or pathophysiological environments. To address the imaging of these various vascular events in vivo, we are using intravital microscopy. Attaching a spinning Nikpow disk confocal head on the IVM system allows much better resolution images to be acquired in vivo than a simple epi-fluorescent microscope. Also, attaching a photoablation unit with a high speed laser point scanner allows a specified region on a blood vessel to be ablated so that subsequent thrombus formation can be monitored in real time. We need to urgently acquire a third upright IVM system which must have spinning disk confocal capabilities in addition to supporting photoablation. The new upright IVM system, which fulfils the requirements, is to be purchased by the Institute of Cardiovascular Sciences (ICVS) at the College of Medical and Dental Sciences (CMDS). It will be housed in a newly refurbished IBR West ground floor facility dedicated to imaging, specifically within a controlled-access facility for intravital research. As the University has invested in excess of one million pounds on refurbishment of the IVM facility and procurement of microscopes, it is critical that we maximise usage. This facility will eventually house 5 IVM systems, one of which is a recently procured (through tender) multiphoton IVM system. We also intend to move 3 previously purchased IVM rigs — 2 upright and 1 inverted microscope, which were all purchased from the same supplier. This facility will be integral to the research of IVM users based in ICVS as well as users based in different institutes in CMDS. In additional to immune and inflammation based research, we also anticipate a wider usage in cell biology research in the College, e.g. imaging of islet cells in pancreatic tissue in vivo, identification of improved agents for labelling and tracking cells, etc. The upright IVM is used to image anaesthetised mouse organs that are better viewed from above, e.g. the heart and kidney. The inverted microscope is practically suited to imaging organs from below, e.g. the liver, mesentery. Some of our complex experiments involve imaging multiple organs in the same animal. To do this, we move the board on which the anaesthetised mouse is positioned from an upright to an inverted microscope (or vice versa). These experiments can be performed with relative ease and in a seamless manner (particularly by new investigators) if the hardware is the same. This also saves on the time and individuals required to train end users — we would only need to train on just one type of hardware/software rather than 2 or more different ones. We currently have limited personnel resources for training purposes. This specification outlines the requirements for a spinning Nipkow disk confocal based-IVM which must be capable of performing multi-colour, 2D and 3D high resolution, real-time (minimum video rate; 30fps) imaging with the potential to perform near simultaneous photoablation. The system must be equipped with at least 4 colour detection channels (3 fluorescent and 1 brightfield), long working distance objective lens suitable for good transmission, high power confocal lasers (100mW minimum). After image capture, the system must be able to reconstruct the acquired images and analyse/render the data for presentation and further analysis. A large platform stage is required allowing an anchor point for vitality devices, buffering perfusion systems and temperature control systems. The platform needs to be designed with speed and sensitivity in mind in order to visualise metabolic or pathological processes following multiple probes simultaneously at 5-times video rate or faster through various living biological samples. It also needs to be compatible with multiple imaging modalities including transmitted light imaging, epifluorescence imaging, and confocal imaging on a single microscope with minimal user manipulation.