Wavelength-Resolved Flow Cytometer Under a Dark-Field Illumination Configuration

Abstract

This paper presents a novel yet high-performance diascopic illumination configuration for simultaneously detecting cells of different sizes and different fluorescence labeling in a microfluidic chip. An objective-type dark-field condenser equipped with a low-cost tungsten bulb light source with continuous wavelengths (400 to 900 nm) and an UV-Vis-NIR spectrometer is used for detecting the multispectral signals from various particles and cells. With this approach, continuous cell counting and spectra analyzing are realized in a single channel without using any spatial filter and delicate optical detectors. Results show that the developed system is capable of identifying different labeled particle and cell samples by extracting the information side-scatter, absorption, and fluorescence from the information-rich spectra. This proposed system provides an efficient multicolor detection for identification and classification of a microflow cytometer chip.

Chip-Based Cytometry Illuminated by a Blade-Shape Continuous Light for Multispectral Detection

“…objective lens (CFI 60 20×/0.75, Nikon, Tokyo, Japan) and a light-stop film as the excited unit. In accordance with the proof-of-concept study performed in [36], the spatial resolution of the cytometer was further enhanced by passing the light emitted from the dark-field condenser through a pinhole prior to entering the high N.A. objective lens.…”

“…A dark-field configuration was also used to quantify and characterize particles and cells in accordance with their light scattering properties [35]. The concept for developing a simple yet effective technique for the simultaneous detection of mixed samples comprising cells/particles with different sizes and with different fluorescence labels on a microfluidic chip without the need for spatial filters or delicate optical components has been reported [36]. In the present study, an objective-type dark-field condenser equipped with a white light source with continuous wavelengths (400-900 nm) is used to induce scattered light and fluorescence signals from particles or cells as they pass through the interrogation region of the microfluidic chip.…”