Hyperspectral
Microscopy
Visible Near Infrared (VNIR) and
Short Wave Infrared (SWIR)
CytoViva’s Hyperspectral Microscope technology was specifically developed for spectral characterization and spectral mapping of nanoscale samples imaged with the patented CytoViva darkfield-based microscope. In addition, this hyperspectral imaging technology supports a wide range of other types of samples, from micro to macro in scale.
Hyperspectral microscope images appear very similar to a traditional optical microscope image with one important difference. Each pixel of a hyperspectral image provides the complete reflectance spectral response of that pixel’s spatial area within the VNIR or SWIR spectral range. This enables nondestructive spectral measurements of nanoscale elements in the full spatial context of the sample image.
At 100x magnification, a hyperspectral microscope image may contain as many as 700,000 pixels, each as small as 128nm each. This hyperspectral data is recorded at approximately 2nm of spectral resolution in the VNIR range, enabling minute spectral differences to be measured from pixel to pixel within the image.
Hyperspectral microscope images can be captured of both biological and materials-based nanoscale samples. These nanoscale materials may be integrated in a wide range of biological or materials based environments. See below an example of AuNPs in ex-vivo lymph node tissue. In this example, hyperspectral imaging makes it possible to quickly identify and map the AuNPs present in the tissue and provides a class distribution confirming the total area where AuNPs are present.
Hyperspectral Image of AuNPs in Tissue
AuNP Spectra Mapped (red) in Tissue
Spectral Response of AuNPs and Tissue
Class Distribution of Tissue Area Mapped for AuNP
These hyperspectral images are created in a line scan or “pushbroom” fashion, by moving the sample across the field of view of the microscope and spectrograph via an automated translational microscope stage. Typically these hyperspectral images (such as the one above) are created in seconds or minutes, depending on the required exposure. Components for the microscopy based hyperspectral imaging system include a specialized light source, automated translational stage, transmission diffraction grating spectrograph and camera. These components are integrated to work together with highly functional image capture and analysis software. This proprietary software provides the ability to compare spectra within a sample image or among large numbers of samples. It can also build a spectral library of unique samples elements and using this spectral library, these sample elements can then be mapped in subsequent samples.
CytoViva hyperspectral imaging can be acquired in either the visible near-infrared (VNIR 400 nm – 1,000 nm) wavelength ranges as well as in the short wave infrared (SWIR 900 nm – 1,700 nm) wavelength ranges.
See below a system configuration for hyperspectral imaging of macro-scale samples that do not require microscopy level imaging.