Development and characterization of an integrated silicon micro flow cytometer

Abstract

This paper describes an innovative integrated micro flow cytometer that presents a new arrangement for the excitation/detection system. The sample liquid, containing the fluorescent marked particles/cells under analysis, is hydrodynamically squeezed into a narrow stream by two sheath flows so that the particles/cells flow individually through a detection region. The detection of the particles/cells emitted fluorescence is carried out by using a collection fiber placed orthogonally to the flow. The device is based on silicon hollow core antiresonant reflecting optical waveguides (ARROWs). ARROW geometry allows one to use the same channel to guide both the sample stream and the fluorescence excitation light, leading to a simplification of the optical configuration and to an increase of the signal-to-noise ratio. The integrated micro flow cytometer has been characterized by using biological samples marked with standard fluorochromes. The experimental investigation confirms the success of the proposed microdevice in the detection of cells.

Detection of unlabeled particles in the low micrometer size range using light scattering and hydrodynamic 3D focusing in a microfluidic system

“…It is also possible that several particles passed simultaneously. The achieved counting rates of this device compare well to other on‐chip cytometers, reporting counting rates of 0.4, 4–25, and <400 Hz [], respectively; in all cases, however, for larger particles. Even though both 2‐μm and 1‐μm particles could be detected separately, the large dispersion in peak height makes it, at the current state, unfeasible to perform measurements on solutions containing a mixture of both size particles.…”

“…Miniaturized flow cytometry using microfluidic principles provides an excellent detection platform with reduced sample consumption and represents an inexpensive alternative for bioparticle sizing and scattered light analysis []. Recently, with the help of microfabrication technology, flow cytometers have been miniaturized for bioparticle detection, or cell sorting and quantification based on various techniques []. Still, the most commonly used transduction signals in optical detection are fluorescence [].…”

Fiber‐free coupling between bulk laser beams and on‐chip polymer‐based multimode waveguides

“…We have demonstrated that particles down to 1 mm can be detected and counted reliably at 100 Hz for concentrations below 300 particles/mL. The achieved performance corresponds very well to other presented on-chip cytometers, with counting rates of 0.4, 4-25 and o400 Hz [14][15][16] respectively, though in all cases for much larger particles. It has been shown how the on-chip lenses can be used both for focusing the light directly at the point of detection and to couple light in and out of waveguides.…”

The good, the bad, and the tiny: a review of microflow cytometry

“…This is due to the inherent obstacle faced by the field of microfluidics-effective on-chip miniaturization of all the components necessary for manipulation of fluids. External pressure-driven pumps often used in microflow cytometry applications include syringe pumps [7][8][9][10][11][12][13] and positively or negatively pressurized reservoirs using a compressed gas source or vacuum pump [14]. Passive pumping methods such as gravity-driven flow have also been used [15][16][17].…”