A microfluidic biosensor to electrically enumerate blood cells at point-of-care for infectious disease diagnosis and management
type: CreativeWork
description: Cell counting finds many applications in diagnostics of many diseases. One of the most common tests recommended by the physicians is complete blood cell count (CBC). In chemotherapy and radiation therapy, the blood cell production needs to be monitored. Inflammation, leukemia, tissue injury, bone marrow failure and immunodeficiency can be identified by the irregular WBC counts and their differentials. Thus, a microfluidic, disposable, economical CBC would help in monitoring all these diseases with more efficiency and care. Cell counting in general, and ability to count the specific cells, would greatly help in clinical diagnostics. Currently, flow cytometers and hematology analyzers are used for this purpose, but they have not been able to penetrate in the resource-limited settings around the world because of being expensive and because they require trained technicians to operate. Over many years, people have developed microfluidic devices for cell counting, which could provide a portable and economical solution to the problem of cell counting at point-of-care. In this dissertation, we present a technique for counting the white blood cells and differentiating some of its sub-types within a microfluidic device. Starting with the whole blood, the red blood cells are lysed by saponin and formic acid. Quenching solution composed of phosphate buffer saline is infused in the device to halt the lysing process and maintain the pH of the solution. The remaining white blood cells are then passed across microfabricated electrodes within a microfluidic channel. The impedance is measured at 303 kHz and 1.7 MHz signals. Cells are captured in a capture chamber where the specific antibody is immobilized. The remaining cells are counted again and the difference in cell counts give the number of captured cells. We have counted CD4 and CD8 T cells from our biochip using healthy and HIV infected blood samples. The cell counts from the biochip are compared with those from the flow cytom…
abstract: Cell counting finds many applications in diagnostics of many diseases. One of the most common tests recommended by the physicians is complete blood cell count (CBC). In chemotherapy and radiation therapy, the blood cell production needs to be monitored. Inflammation, leukemia, tissue injury, bone marrow failure and immunodeficiency can be identified by the irregular WBC counts and their differentials. Thus, a microfluidic, disposable, economical CBC would help in monitoring all these diseases with more efficiency and care. Cell counting in general, and ability to count the specific cells, would greatly help in clinical diagnostics. Currently, flow cytometers and hematology analyzers are used for this purpose, but they have not been able to penetrate in the resource-limited settings around the world because of being expensive and because they require trained technicians to operate. Over many years, people have developed microfluidic devices for cell counting, which could provide a portable and economical solution to the problem of cell counting at point-of-care. In this dissertation, we present a technique for counting the white blood cells and differentiating some of its sub-types within a microfluidic device. Starting with the whole blood, the red blood cells are lysed by saponin and formic acid. Quenching solution composed of phosphate buffer saline is infused in the device to halt the lysing process and maintain the pH of the solution. The remaining white blood cells are then passed across microfabricated electrodes within a microfluidic channel. The impedance is measured at 303 kHz and 1.7 MHz signals. Cells are captured in a capture chamber where the specific antibody is immobilized. The remaining cells are counted again and the difference in cell counts give the number of captured cells. We have counted CD4 and CD8 T cells from our biochip using healthy and HIV infected blood samples. The cell counts from the biochip are compared with those from the flow cytom…
author: Hassan, Umer
language: en
keywords: Complete Blood Cell count, HIV/ AIDS Diagnosis, CD4, CD8 cell counting, Coincidence detection, Surface capture of cells, Sepsis Diagnosis, CD64 Expression
date published: 2015-07-22T22:45:27Z
date modified: 2026-07-22T22:26:12Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/78743