A cell counting/sorting system incorporated with a microfabricated flow cytometer chip

Abstract

Flow cytometry is a popular technique for counting and sorting individual cells. This study presents and demonstrates a new cell counting/sorting system integrated with several essential components including a micromachined flow cytometer chip device, an optical detection system and a data analysis and control system to achieve the functions of cell sample injection, optical signal detection and cell collection. By using MEMS technology, we have integrated several microfluidic components such as micro pneumatic pumps/valves onto a polymer-based chip device. Three pneumatic micropumps are used to provide the hydrodynamic driving force for both sample and sheath flows such that hydrodynamic flow focusing can be achieved, and a micro flow switch device comprising three pneumatic microvalves located downstream of the micro sample flow channel is used for cell collection. Cell samples of human lung cancer cells labelled with commercially available fluorescent dyes have been detected and collected successfully utilizing the developed device. The real-time image of dye-labelled cell samples being excited and detected can be monitored and observed through the LCD panel by a custom designed CCD/APD holder and moving stage. Finally, micro flow switch devices were used to successfully sort the cells into the desired outlet channel, and the counting results of the specific cell samples were monitored through the counting panel. The current study focuses on the setup of the overall system. The proposed flow cytometer system has several advantages such as portability, low cost and easy operation process. The size of the system is 37 cm × 16 cm × 18 cm and the weight is 3.5 kg. The error rate of counting and sorting was 1.5% and 2%, respectively. The sorting frequency of the microvalve device is calculated to be 120 cells min−1. The developed microfluidic chip device could be a promising tool for cell-based application fields such as profiling, counting and sorting.

Recent advances in microscale pumping technologies: a review and evaluation

“…A single electromagnetic valve and pneumatic source was incorporated into a three-chamber design by Huang et al (2006a). A similar pump actuated by a single pneumatic source employed a serpentine pneumatic channel where the intersection of the pneumatic channel and fluid channel constituted areas of membrane deflection (Yang et al 2006). Seven intersections provided seven stages of peristaltic actuation.…”

“…For large throughputs, high flow rates would also be needed; however, the current limitation appears to be the sorting technique as opposed to pumping of the fluid. As an example, s-shaped peristaltic pumps have found application in cell sorting and cytometry (Yang et al 2006).…”

Development of a "genome-proxy" microarray for profiling marine microbial communities, and its application to a time series in Monterey Bay, California

“…In addition, advances in FCM, such as equipment miniaturization, are bringing down costs and enabling novel field deployments (Gruden et al, 2004, Yang et al, 2006. Perhaps pinnacle among these field efforts are the "FlowCytoBot" (Olson and Sosik, 2007;Sosik and Olson, 2007) and "Cytosub" (Thyssen et al, 2008) which use robotics and autonomous sampling devices to enable in situ real-time FCM.…”

Development of Rapid Assessment Method to Determine Bacterial Viability Based on Ultraviolet and Visible (UV-Vis) Spectroscopy Analysis Including Application to Bioaerosols

“…Although the fluorochromasia method and dye-exclusion test allow live and dead cells to be easily distinguished, these methods require a step to stain cells, and an additional step to analyze the stained cells such as fluorescence spectroscopy, fluorescence microscopy, or the use of fluorescence microplate readers and flow cytometry (Molecular Probes Inc., 2004;Perfetto et al, 2006;Barbosa et al, 2008). Yang et al (2006) developed a flow cytometer system incorporated with an easily operated microfabricated flow cytometer chip. Operation of a traditional flow cytometer still relies on the need for specialized personnel and complicated sample pretreatment procedures.…”