CAPTURE: A NEW APPROACH TO BREAST CANCER DIAGNOSIS
TECHNOLOGY
INFRARED &Â RAMAN SPECTROSCOPY
The mIRage IR microscope combines Optical Photothermal Infrared (O-PTIR) spectroscopy and Raman micro-spectroscopy to provide simultaneous IR and Raman spectra at a spatial resolution of 0.5 µm.
The system (as shown on the left) is composed of a mIRage IR microscope (Photothermal Spectroscopy Corporation, Santa Barbara, CA) with a x10 reflective objective and a X40 cassegrain objective. Four tuneable pulsed mid-IR quantum cascade lasers (QCL) are used to induce the photothermal effect covering the fingerprint region from 1800 to 800 cm-1. The Horiba Scientific iHR 320 Raman spectrometer with a 785 nm laser probe is integrated within this system.
This system offers a high spatial resolution beyond the diffraction limit of the IR wavelengths (0.5µm vs 5-12 µm) of standard lab based IR systems, and the QCL system enables selection of individual IR wavelengths, for single frequency imaging.
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These facilities can be found at the University of Exeter, with more information available at the following pages: Exeter Contrast Facility and BioSpec: Biomedical Spectroscopy Labs.
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SPECTROSCOPY DATA
Raman maps produced from analysing different areas of a microcalcification.
X-RAY DIFFRACTION (XRD)
X-ray diffraction data is collected at Diamond Light Source, Didcot, UK on beamline I18. The bespoke sample holders are clamped perpendicular to the X-ray beam on a motorized stage and measurements made in transmission using a beam spot size of 10 × 10 μm, and an energy of 10.0 keV.
XRD DATA
2D X-ray diffraction data, showing rings corresponding to scattering from hydroxyapatite, one of the main mineral phases identified in breast calcifications.
SCANNING ELECTRON MICROSCOPY (SEM)
Scanning electron microscopy (SEM) is a useful tool to investigate the morphology of breast calcifications and can be combined with elemental analyses such as energy dispersive spectroscopy (EDS) to determine the elemental composition of calcifications and produce maps of individual elements across the samples.
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For this work, SEM analysis will be carried out on a Hitachi SU3500 system. Traditionally, samples for electron microscopy needed to be coated in heavy metals in order to achieve sufficient contrast and reduce charging effects, but the use of the variable pressure mode on this system permits SEM analysis of biological samples such as breast tissue biopsies without complicated sample preparation.
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These facilities can be found at Cranfield University, with further information available at Cranfield Microscopy Services and Facilities.
SEM DATA
High resolution SEM image of a breast microcalcification.