Standard immunofluorescence (IF) staining is labor-intensive, time-consuming and suffers from inflexibility and poor multiplicity. To overcome these limitations, we proposed a deep learning (DL) approach for virtual IF staining with high multiplicity and specificity from label-free reflectance microscopy. Our results show that DL-enabled label-free IF microscopy can predict characteristic subcellular features during different cell cycles and reveal cellular phenotypes with high accuracy.
LED array microscopy is an emerging platform for computational imaging . Existing LED array systems often exploit transmission imaging geometries of standard brightfield microscopes that leave the rich backscattered field undetected. Here, we develop an LED array reflectance microscope capturing the sample’s backscattered signal. In particular, we demonstrate multimodal brightfield, darkfield, and differential phase contrast imaging on fixed and living biological specimens including Caenorhabditis elegans (C. elegans), zebrafish embryos, and live cell cultures. Video-rate multimodal imaging records real-time features of freely-moving C. elegans and the fast beating heart of zebrafish embryo. Our new reflectance mode is a valuable addition to the LED array microscopic toolbox.
The retina, as part of the central nervous system, has distinct anatomical and structural properties for its visual function. Light scattering spectroscopy, while widely used for tissue structural characterization and disease diagnosis, has been relatively unexplored in the living retina. Recently, we have developed a fiber-based visible and near-infrared optical coherence tomography system (vnOCT) for in vivo retinal imaging, to uniquely measure a spectroscopic marker (VN ratio) sensitive to nanoscale pathological changes. In the present study, we applied vnOCT in an animal model of glaucoma (dexamethasone-induced ocular hypertension mouse) and tested the capabilities of four optical markers, VN ratio, peripapillary retinal nerve fiber layer (RNFL) thickness, total retinal blood flow, and hemoglobin oxygen saturation (sO2), for the detection of retinal ganglion cell (RGC) damage in association with ocular hypertension. We found that RNFL-RGC VN ratio and arteriovenous (A-V) sO2 are capable of detecting early retinal alteration in ocular hypertensive eyes, preceding measurable change of RNFL thickness. This study suggests a potential clinical application of vnOCT in early detection of glaucoma.