On-chip counting the number and the percentage of CD4+ T lymphocytes

Abstract

A novel technique is reported for counting the number and the percentage of CD4+ T lymphocytes in a polydimethylsiloxane (PDMS) microchannel. This system integrates optical fluorescence detection with resistive pulse sensing enhanced by a metal oxide semiconductor field effect transistor (MOSFET). The MOSFET signal indicates the total number of the cells passing through the detection channel, while the concurrent fluorescence signal records only the number of cells tagged with a specific fluorescent dye. The absolute count of the CD4+ T cells and its percentage to the total lymphocytes can be analyzed by combining the two counting results, which shows comparable accuracy to those from the commercial flow cytometer. The fastest observed counting rate for a single-channel microchip is 8.5 cells per second. This technique is highly promising as it could greatly reduce the cost for HIV diagnosis and treatment and make it accessible to resource-poor developing countries.

Micro- and Nanotechnology for HIV/AIDS Diagnostics in Resource-Limited Settings

“…Wang et al integrated a commercial MOSFET with optical fluorescence detection to determine the percent of CD4+ T cells among a total population of lymphocytes [114]. They have also created a similar system replacing the MOSFET with a twostage differential amplification system [115], [116].…”

Microfluidic applications of functionalized magnetic particles for environmental analysis: focus on waterborne pathogen detection

“…Aligned with the requirement of obtaining accurate results in the shortest possible time, it is desirable to implement the standard method using an automated system that minimizes human interference and reduces possibilities of inducing errors. Several efforts have been made to develop microfluidics-based cell counting devices by integrating fluorescence detection into the microfabricated chips (Wang et al 2008;Lin et al 2008). Rodriguez et al (2005) developed a prototype for counting of CD4 cells by capturing the stained cells on a membrane within a microchip followed by imaging the captured cells and converting the digital image into a cell count using a computer algorithm.…”

Microfluidic differential resistive pulse sensors

“…A minimum volume ratio of 0.006% was achieved, which is ten times more sensitive than those reported in the literature. As a real application, the authors further furbished this system with a fluorescence optical detection function and realized on-chip counting of the total number and the percentage of the fluorescence-labeled cluster of differentiation 4 (CD4 1 ) T cells [20]. In this paper, we report another resistive pulse-sensing scheme using a symmetric mirrorchannel structure and differential amplifiers.…”