We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
PURITAN MEDICAL

Download Mobile App




Events

09 Apr 2024 - 12 Apr 2024
15 Apr 2024 - 17 Apr 2024
23 Apr 2024 - 26 Apr 2024

Novel Biochip Combines Antibody Binding and Electronic Counting to Simplify Diagnosis of HIV/AIDS

By LabMedica International staff writers
Posted on 20 Mar 2016
Print article
Image: Close-up of the differential immuno-capture biochip (Photo courtesy of Dr. Umer Hassan, University of Illinois).
Image: Close-up of the differential immuno-capture biochip (Photo courtesy of Dr. Umer Hassan, University of Illinois).
A recent paper described the construction of a microchip biosensor that uses immuno-capture technology to detect sub-populations of immune leukocytes.

Investigators at the University of Illinois (Urbana-Champaign, USA) developed the small, disposable biochip in order to differentiate and count CD4+ and CD8+ T-cells, which is a key factor in diagnosing HIV/AIDS.

The prototype biochip is built around a capture chamber coated with anti-CD4+ antibodies. In addition, it has separate ports for lysing reagents and quenching buffers that preserve the leukocytes for counting by co-planar platinum microfabricated electrodes.

In practice, ten microliters of whole blood was infused into the biochip. The red cells were removed by lysis, and leukocytes were preserved using quenching buffers. The leukocytes were counted while passing over a counting device comprising co-planar platinum microfabricated electrodes on the way into the capture chamber. CD4+ T-cells were captured as they interacted with specific antibodies in the capture chamber. Leukocytes that were not captured passed out of the capture chamber and were counted again with a second counter. The difference in the respective cell counts gave the number of cells captured.

While this paper provided a comprehensive stepwise protocol to replicate the biosensor for CD4+ and CD8+ cell counts, the biochip could be adapted to enumerate other specific cell types such as somatic cells or cells from tissue or liquid biopsies. Capture of other specific cells would require immobilization of their corresponding antibodies within the capture chamber.

In clinical trials, the differential immuno-capture biochip achieved more than 90% correlation with flow cytometry for both CD4+ and CD8+ T-cells using HIV infected blood samples.

Production of the prototype biochip required approximately 24 hours. A one-time optimization of the cell capture step took six to nine hours, and the final cell counting experiment required 30 minutes to complete.

"An important diagnostic biomarker for HIV/AIDS is the absolute count of the CD4+ and CD8+ T lymphocytes in the whole blood. The current diagnostic tool—a flow cytometer—is expensive, requires large blood volume, and a trained technician to operate," said senior author Dr. Rashid Bashir, professor of bioengineering at the University of Illinois. "We have developed a microfluidic biosensor based on a differential immuno-capture electrical cell counting technology to enumerate specific cells in 20 minutes using 10 microliters of blood."

The biochip protocol was published in the March 10, 2016, online edition of the journal Nature Protocols.

Related Links:
University of Illinois


Platinum Member
COVID-19 Rapid Test
OSOM COVID-19 Antigen Rapid Test
One Step HbA1c Measuring System
GREENCARE A1c
Anti-Cyclic Citrullinated Peptide Test
GPP-100 Anti-CCP Kit
Gold Member
ADAMTS-13 Protease Activity Test
ATS-13 Activity Assay

Print article

Channels

Clinical Chemistry

view channel
Image: Reaching speeds up to 6,000 RPM, this centrifuge forms the basis for a new type of inexpensive, POC biomedical test (Photo courtesy of Duke University)

POC Biomedical Test Spins Water Droplet Using Sound Waves for Cancer Detection

Exosomes, tiny cellular bioparticles carrying a specific set of proteins, lipids, and genetic materials, play a crucial role in cell communication and hold promise for non-invasive diagnostics.... Read more

Molecular Diagnostics

view channel
Image: MOF materials efficiently enrich cfDNA and cfRNA in blood through simple operational process (Photo courtesy of Science China Press)

Blood Circulating Nucleic Acid Enrichment Technique Enables Non-Invasive Liver Cancer Diagnosis

The ability to diagnose diseases early can significantly enhance the effectiveness of clinical treatments and improve survival rates. One promising approach for non-invasive early diagnosis is the use... Read more

Hematology

view channel
Image: The low-cost portable device rapidly identifies chemotherapy patients at risk of sepsis (Photo courtesy of 52North Health)

POC Finger-Prick Blood Test Determines Risk of Neutropenic Sepsis in Patients Undergoing Chemotherapy

Neutropenia, a decrease in neutrophils (a type of white blood cell crucial for fighting infections), is a frequent side effect of certain cancer treatments. This condition elevates the risk of infections,... Read more

Pathology

view channel
Image: The OvaCis Rapid Test discriminates benign from malignant epithelial ovarian cysts (Photo courtesy of INEX)

Intra-Operative POC Device Distinguishes Between Benign and Malignant Ovarian Cysts within 15 Minutes

Ovarian cysts represent a significant health issue for women globally, with up to 10% experiencing this condition at some point in their lives. These cysts form when fluid collects within a thin membrane... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.