Dark field illumination is normally used for analyzing biological samples consisting of nanomaterials that scatter light to a considerable extent. When combined with hyperspectral imaging, it becomes an exceptional tool to detect the location and composition of nanomaterials embedded in cells.
IMA™, Photon etc’s hyperspectral imager, can be equipped with a high-efficiency dark field condenser and high contrast images of biological samples are generated.
The high throughput of Photon etc’s hyperspectral filter enables rapid acquisition of spectrally resolved high resolution images. As the camera captures the complete area in the field of view, it is possible to collect spectral and spatial information in real time, with the possibility of recording spectrally resolved videos to follow the dynamics of cells and luminescent nanoscale components.
PHySpec™, Photon etc software, allows principal component analysis (PCA) in order for identifying the smallest variations of single and aggregated nanoparticles.
Analysis of Nanomaterials in Cancer Cells
With the purpose of showing the capabilities of IMA to analyze nanomaterials in biological systems, a sample of MDA-MB-23 human breast cancer cells has been tagged with 60nm gold nanoparticles (GNPs) and exposed to a dark field illumination on the entire field of view as shown in Figure 1.
Figure 1. Dark-field image of human breast cancer cells tagged with gold nanoparticles (60 nm size).
With an objective of 60x, imaging of 150×112µm area was done with a step of 2nm and an exposition time of 2s per wavelength. The complete analysis took only a few minutes, for over one million spectra, each of them covering the whole visible spectrum.
Typically cells have a flat scattering spectrum, whereas GNPs show a sharp peak around 550nm. Figure 2 shows the 550 nm image extracted from the dark field hyperspectral cube of the breast cancer. A green coloring after PCA software processing mark the GNPs.
Figure 2. Monochromatic image at 550 nm. GNPs marked in green after PCA.
The magnification of a breast cancer cell as shown in Figure 3a and the spectra of the regions containing GNPs (some examples in Figure 3b) confirmed the presence of single 60 nm NPs (peak at 550 nm) and their aggregates (peaks red-shifted). The hyperspectral camera did not detect any GNPs in the areas between the cells.
Figure 3. Magnification of a breast cancer cell (a) and spectra of GNPs in different areas (b).
Results provided by: David Rioux, Éric Bergeron and Michel Meunier, at École Polytechnique, Montreal, Quebec, Canada.
About Photon etc
Photon etc. offers state-of-the-art photonic and optical research instrumentation, from laser line tunable filters to widefield and microscopy hyperspectral imaging systems. Its patented spectral imaging and optical sensing technologies provide solutions for a wide variety of scientific and industrial applications. From material analysis to medical imaging, Photon etc.’s expertise and spirit of innovation allow the exploration of uncharted territories.
Photon etc. aims to provide each researcher, engineer and technician with access to the latest innovations in optical and photonic instrumentation. As pioneers in Bragg-based hyperspectral imaging, Photon etc. offers state-of-the-art instruments, driven by its clients’ desires to surpass limitations in measurement and analysis.
Inspired by the scientific creativity found in Montreal and Quebec, Photon etc. promotes open and collaborative innovation and excellence. The dynamic team of this company is proud to offer to its clients innovative and reliable instruments, based on the latest scientific advances in photonics and optics. At Photon etc., the primary wish is to develop a long term relationship with the clients by providing products adapted to their specific needs, combined with personalized service and support.
This information has been sourced, reviewed and adapted from materials provided by Photon etc.
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