When imaging histology samples using a microscope at high resolution, 3D scans are often acquired by shining a flat beam of light through the target volume. While this has allowed for a multitude of discoveries, the technique still suffers greatly from the light scattering through the sample and washing out the sharpness of the image. This is most noticeable in thicker specimens that require light to travel through a lot of material. Tagging markers can be used to overcome some of this fuzziness, but they are often incompatible with the future viability of a living sample. Now researchers at the University of Illinois have developed a new imaging technique that significantly improves the quality of such microscopy images by controlling and taking into account the scattering of the light.
Dubbed as gradient light interference microscopy (GLIM), the technology modulates the depth of the sample through which the light beam is allowed to penetrate through. Light is passed through at different intensities, effectively lighting up different volumes of the sample. The sample is also rotated to allow the scanning system to image it from different angles. All this data is then compiled and a 3D rendering is generated by a computer.
To wow the world with the new capability, the Illinois researchers were able to peer into a live embryo of a cow at high resolution and without harming the organism.
A bit about the technology according to a study abstract in Nature Communications:
GLIM exploits a special case of low-coherence interferometry to extract phase information from the specimen, which in turn can be used to measure cell mass, volume, surface area, and their evolutions in time. Because it combines multiple intensity images that correspond to controlled phase shifts between two interfering waves, gradient light interference microscopy is capable of suppressing the incoherent background due to multiple scattering.
Study in Nature Communications: Gradient light interference microscopy for 3D imaging of unlabeled specimens…
