Team developing mobile DNA test for HIV

June 5, 2014 by Mike Williams
Rice graduate students Zachary Crannell, left, and Brittany Rohrman are leading Rice University bioengineers in an effort to develop an efficient test to detect signs of HIV and its progress in patients in low-resource settings. Credit: Jeff Fitlow/Rice University

(Phys.org) —Rice University bioengineers are developing a simple, highly accurate test to detect signs of HIV and its progress in patients in resource-poor settings.

The current gold standard to diagnose HIV in infants and to monitor viral load depends on and technical expertise generally available only in clinics, said Rice bioengineer Rebecca Richards-Kortum. The new research features a nucleic acid-based test that can be performed at the site of care.

Richards-Kortum, director of the Rice 360˚: Institute for Global Health Technologies, and her colleagues reported their results in the American Chemical Society journal Analytical Chemistry.

The proof-of-concept work by co-lead authors Zachary Crannell and Brittany Rohrman, both graduate students in the Richards-Kortum lab, follows their similar technique to detect the parasite that causes the diarrheal disease cryptosporidiosis, reported earlier this year.

The new technique would replace a complex lab procedure based on with one that relies on recombinase polymerase amplification (RPA), a method to quickly amplify – that is, multiply – genetic markers found in blood to levels where they can be easily counted. In a test the team calls qRPA, a specific sequence in HIV DNA is targeted and tagged with fluorescent probes that can be seen and quantified by a portable machine. Software analysis of the fluorescing DNA allows clinicians to determine with great accuracy whether the virus is present in a patient's blood and/or how much is there.

The researchers calibrated the test by also amplifying an internal positive control not found in human blood. "It's amplified by the same primers as the HIV sequence, so it tells us that the assay is working properly," Rohrman said.

The students originally intended their work to look for HIV in infants, but the technique can also help to track in older patients. "It's important for clinicians to be able to quantitatively monitor patients' viral loads in order to ensure the disease is responding to therapy," Crannell said.

To be clinically viable, a DNA-based test for HIV has to be able to quantify virus loads over four orders of magnitude, from very low to very high, the researchers said. They reported the Rice easily meets that goal.

They are developing tools for low-resource settings where high-tech lab equipment is not available. Although they used a thermal cycler, the researchers are working on a technique that will keep the entire procedure between room and body temperatures so that it can be performed at the point of care in the developing world.

The research was funded by a grant from the Bill & Melinda Gates Foundation through the Grand Challenges in Global Health Initiative.

Explore further: Quick test finds signs of diarrheal disease

More information: Paper: pubs.acs.org/doi/abs/10.1021/ac5011298

Related Stories

Quick test finds signs of diarrheal disease

February 6, 2014

Bioengineers at Rice University and the University of Texas Medical Branch (UTMB) at Galveston have developed a simple, highly sensitive and efficient test for the diarrheal disease cryptosporidiosis that could have great ...

New technique tracks proteins in single HIV particle

May 5, 2014

An interdisciplinary team of scientists from KU Leuven in Belgium has developed a new technique to examine how proteins interact with each other at the level of a single HIV viral particle. The technique allows scientists ...

Recommended for you

Brazilian wasp venom kills cancer cells by opening them up

September 1, 2015

The social wasp Polybia paulista protects itself against predators by producing venom known to contain a powerful cancer-fighting ingredient. A Biophysical Journal study published September 1 reveals exactly how the venom's ...

Naturally-occurring protein enables slower-melting ice cream

August 31, 2015

(Phys.org)—Scientists have developed a slower-melting ice cream—consider the advantages the next time a hot summer day turns your child's cone with its dream-like mound of orange, vanilla and lemon swirls with chocolate ...

Antibody-making bacteria promise drug development

August 31, 2015

Monoclonal antibodies, proteins that bind to and destroy foreign invaders in our bodies, routinely are used as therapeutic agents to fight a wide range of maladies including breast cancer, leukemia, asthma, arthritis, psoriasis, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.