Time-stretch microscopy on a DVD for high-throughput imaging cell-based assay

Abstract

Cell-based assay based on time-stretch imaging is recognized to be well-suited for high-throughput phenotypic screening. However, this ultrafast imaging technique has primarily been limited to suspension-cell assay, leaving a wide range of solid-substrate assay formats uncharted. Moreover, time-stretch imaging is generally restricted to intrinsic biophysical phenotyping, but lacks the biomolecular signatures of the cells. To address these challenges, we develop a spinning time-stretch imaging assay platform based on the functionalized digital versatile disc (DVD). We demonstrate that adherent cell culture and biochemically-specific cell-capture can now be assayed with time-stretch microscopy, thanks to the high-speed DVD spinning motion that naturally enables on-the-fly cellular imaging at an ultrafast line-scan rate of >10MHz. As scanning the whole DVD at such a high speed enables ultra-large field-of-view imaging, it could be favorable for scaling both the assay throughput and content as demanded in many applications, e.g. drug discovery, and rare cancer cell screening. Balakrishnan, C.-Y. Wang, P. Yaswen, A. Goga, and Z. Werb, "Single-cell analysis reveals a stem-cell program in human metastatic breast cancer cells," Nature 526(7571), 131-135 (2015).

Label-free detection of cellular drug responses by high-throughput bright-field imaging and machine learning

“…Despite its high throughput, the spatial resolution of our microscope remained at the diffraction limit of 780 nm 15 , which is comparable to that of conventional optical microscopes. To the best of our knowledge, this is the first experimental demonstration of an imaging flow cytometer capable of taking diffraction-limited images at a theoretical throughput of more than 100,000 cells/s, which is challenging even for conventional non-imaging flow cytometry 16 – 18 . The combination of such high-throughput and high-resolution capabilities allows us to use only bright-field images and simple machine learning algorithms to identify the miniscule drug-induced morphological change of cells with high accuracy.…”

Quantitative Phase Imaging Flow Cytometry for Ultra‐Large‐Scale Single‐Cell Biophysical Phenotyping

“…This could open a new paradigm shift in SCA in which systematic study of complex correlation between biophysical and biomolecular signatures of single cells. Furthermore, multi‐ATOM can also be extended to the imaging format involving adherent cells on a solid platform (e.g., the spinning imaging platform )—bringing the ultra‐large‐scale single‐cell imaging capability to a new paradigm in continuous long‐term label‐free single‐cell studies.…”

Effects of Flow‐Induced Microfluidic Chip Wall Deformation on Imaging Flow Cytometry

“…There was one difference between our setup and that described by Tang et al ( ), we connected a microfluidic device by a PEEK connector and tubing, and we reinforced these connections using a cement adhesive (Supporting Information Fig. S2).…”

“…To detect and visualize cell‐to‐cell variations rapidly in response to the effects of drugs, genes, and other perturbations, quick imaging of individual cells in large populations and analysis of morphological and biochemical properties of these individual cells are desired. Therefore, several high‐speed imaging methods have been developed for high‐throughput single‐cell analysis, such as fluorescent imaging , bright‐field imaging with high‐speed charge coupled device and complementary metal‐oxide‐semiconductor sensors , Raman spectroscopy , optofluidic time‐stretch (OTS) microscopy , and multicolor fluorescent, bright‐field, and dark‐field imaging . Among them, laser‐based high‐throughput fluorescent imaging has been used in commercialized flow cytometers, allowing applications for counting and sorting cells by cellular properties (e.g., size and surface adhesion), detecting microorganisms with multidrug resistance and various molecules (e.g., biomarkers, proteins, DNA and RNA), and measuring enzyme activity .…”