Gradient light interference microscopy for 3D imaging of unlabeled specimens

Abstract

Multiple scattering limits the contrast in optical imaging of thick specimens. Here, we present gradient light interference microscopy (GLIM) to extract three-dimensional information from both thin and thick unlabeled specimens. 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. GLIM can potentially become a valuable tool for in vitro fertilization, where contrast agents and fluorophores may impact the viability of the embryo. Since GLIM is implemented as an add-on module to an existing inverted microscope, we anticipate that it will be adopted rapidly by the biological community.

Effects of substrate patterning on cellular spheroid growth and dynamics measured by gradient light interference microscopy (GLIM)

“…GLIM generates quantitative phase gradient images of the sample with high depth sectioning capability. Quantitative phase methods often use coherent light sources that hamper the contrast of the images due to scattering artifacts . GLIM resolves this problem by using low‐coherence interferometry with white light, enabling extremely sensitive measurements.…”

“…The recurrent drawback with laser instruments, however, has been speckles and other coherent artifacts resulting from coherent light sources . During the past decade, several white light‐based methods have been devised to obtain speckle‐free images . In particular, spatial light interference microscopy (SLIM) and gradient light interference microscopy (GLIM) have been used successfully to study the 3D morphology of various sample types, such single cells , embryos , red blood cells and neural networks .…”

“…During the past decade, several white light‐based methods have been devised to obtain speckle‐free images . In particular, spatial light interference microscopy (SLIM) and gradient light interference microscopy (GLIM) have been used successfully to study the 3D morphology of various sample types, such single cells , embryos , red blood cells and neural networks . Very recently, SLIM has been used for high‐throughput single cell weight phenotyping in biomass producing cell populations .…”

Label‐free optical projection tomography for quantitative three‐dimensional anatomy of mouse embryo

“…Imaging capability of LF‐OPT toward high‐throughput and phenotype screening would be more accelerated if deep leaning technique is integrated in image processing procedure. In addition, the contrast and resolution could be further enhanced hiring complementary and advanced imaging technique . Combined with rapid advance of gene editing technology, such as CRISPR/Cas9 system, development of LF‐OPT imaging system will also expand the spectrum of phenotyping of certain types of genetic materials.…”

Topography and refractometry of sperm cells using SLIM

“…QPI is an emerging method that provides quantitative information about transparent specimens, with nanoscale sensitivity and in label-free mode 9 . Various implementations of QPI have been used recently to study the topography of gametes, assuming a certain refractive index [10][11][12][13][14][15][16] . Here, for the first-time to our knowledge, we measure independently the thickness and refractive index of the cells.…”