Experience

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Contents

Positions & Affiliations

Employer Designation Start Date End Date
Micro and Nanotechnology Laboratory, UIUC Research Assistant Aug. 2011 Present
Experimental Physics Laboratory, LUMS Development Engineer Sep. 2010 July 2011
Experimental Physics Laboratory, LUMS Laboratory Instructor July 2009 Aug. 2010
Experimental Physics Laboratory, LUMS Laboratory Engineer Sep. 2008 June 2009
Nestle Pakistan Ltd Intern June 2006 July 2006

Research Experience

HIV/AIDS Diagnostics using BioNanotechnology (2011-Present)

Diagnosing all of the HIV infected people around the globe is one of the biggest challenges the world faces today. Globally 34 million people are infected with HIV/AIDS, and 1.8 million people die of AIDS each year. Almost 70% of them are living in sub-Saharan Africa. The lack of availability of medical infrastructure and expertise required to perform the current standardized test i.e. Flow cytometer, especially in resource limited settings indicates an imminent need to make a portable, low cost diagnostics device.

CD4

When a person contracts HIV, the HIV virus starts killing the CD4 T-lymphocytes which constitutes the main defense of the body. Without the treatment like Antiretroviral therapy (ART) the CD4 T cells continue to decrease till it reaches 200 cells/uL (a clinical definition of AIDS) below which an infectious disease like TB can easily kill the patient. One way to diagnose the HIV is to count the number of CD4 T cells in human blood. We present a differential CD4 T cell lymphocyte counter. The 10uL of blood is infused in the device along with the lysing buffer to lyse the red blood cells. Quenching buffer is then infused to maintain the pH of the solution. The remaining white blood cells pass through the 15 micron counting channel where a set of electrodes generate a pulse for each passage of a cell, thus giving the entrance counts. The cells then passed through a capture chamber to which CD4 Antibody is initially immobilized by adsorption surface chemistry. With optimized shear stress for maximum capture efficiency, the cells flow through the capture chamber and CD4 cells get captured. The remaining cells pass through another counting channel and give the exit count. By taking the differential of the counts, the number of captured CD4 cells is calculated. A high co-relation exists in between the CD4 counts from our device and the control results from the Carle hospital using blood from the healthy people. We are planning to start testing our device on the patient samples as well soon. The project is funded by National Science Foundation and Global Health Initiative at Illinois. The project is being carried out at University of Illinois at Urbana Champaign.

Improvement in Capture Efficiency for Cell Capture Experiments (2011-12)

In Cell capture experiments, capture efficiency is the most critical parameter. The capture efficiency should ideally be 100% such that all the desired should be captured. In our CD4 T cell capture experiments, the planar capture chamber is giving almost 60% of the capture efficiency. The capture efficiency can be increased by using the covalent based surface chemistry, another approach is to change the geometry of the cell capture chamber. We have increased the capture efficiency to almost 90% by placing microposts into the capture chamber to not only create more surface area for cell-to-surface interactions, but to mechanically press the cells against the antibody coated pillars. The following figure illustrates the idea, where cells are forced against and squeezed between pillars, capturing the desired cells. It also shows the preliminary COMSOL simulations of shear stresses in a capture region with pillars. Shear stress along with Pillar diameter, height, and spacing needs to be optimized to maximize the capture efficiency.

Capture


Electrical Flow Metering of Blood for Point-of-Care Diagnostics (2011-12)

We have developed a microfabricated chip that creates a purified white blood cell (WBC) population from whole blood samples and then electrically analyzes the WBCs at the same time as measuring sample volume flown. The flow metering is based on the measurement of the electrical admittance between microelectrodes inside a microfluidic channel. We found that the admittance related to the flow rate linearly. WBC counts which correlated with the flow rate shows how this technique is a viable method in metering and analyzing blood and other biological samples in a point-of-care environment.

Flow

Previous Research & Development Experience (2008-2011)

  • Developing an indigenous RT-PCR setup at the Experimental physics laboratory .
  • Establishment of Quantum Optics Laboratory. Laboratory includes experiments on (single photon counting, coincidence photon detection, Mach Zehnder Interferometer, Quantum key distribution and violation of Bell’s Inequalities).
  • Developed a junior lab experiment, Measuring laser wavelength and refractive index of glass using Michelson Interferometer.
  • Developed ECG, Pulse Oximetry for Physiology lab.
  • Hearing sensitivity & Audiometric measurements.
  • A junior year lab experiment on lattice vibrations, dispersion relations of bare string, mono atomic and diatomic cases.
  • Investigating circular modes in a vibrating string.
  • Designed an experiment, “Electromagnetic Induction and Working of Read-Write Operations in Magnetic Media”.
  • Designed a Pseudo Random Bit Sequence Generator, which is being used in experiments and research projects.

Teaching/ Mentoring Experience

Course Name Term Work Description
PHY310 Experimental Physics-III Spring 2011 Projects supervision
PHY331 Experimental Physics-II Fall 2010 Supervised experiments & evaluated students
EE241 Electronics Laboratory Fall 2009 Mentor for Projects
PHY110 Experimental Physics Laboratory Fall 2008 Instructed experiments & evaluated students
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