Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.

 

DNA and gold particles used to diagnose diseases

04 March 2013, 13:40

A diagnostic "cocktail" containing a single drop of blood, a dribble of water, and a dose of DNA powder with gold particles could mean rapid diagnosis and treatment of the world's leading diseases in the near future.

The cocktail diagnostic is a home-grown brew being developed by University of Toronto's Institute of Biomaterials and Biomedical Engineering (IBBME) PhD student Kyryl Zagorovsky and Professor Warren Chan that could change the way infectious diseases, from HPV and HIV to malaria, are diagnosed.

And it involves the same technology used in over-the-counter pregnancy tests.

"There's been a lot of emphasis in developing simple diagnostics," says IBBME Professor and Canada Research Chair in Nanobiotechnology, Warren Chan. "The question is, how do you make it simple and portable enough?"

Particles used are tiny

The recent winner of the NSERC E.W.R. Steacie Memorial Fellowship, Professor Chan and his lab study nanoparticles: in particular, the use of gold particles in sizes so small that they are measured in the nanoscale. Chan and his group are working on custom-designing nanoparticles to target and illuminate cancer cells and tumours, with the potential of one day being able to deliver drugs to cancer cells.

But it's a study recently published in Angewandte Chemie, a top chemistry journal published out of Germany, that's raising some interesting questions about the future of this relatively new frontier of science.

Zagorovsky's rapid diagnostic biosensor will allow technicians to test for multiple diseases at one time with one small sample, and with high accuracy and sensitivity. The biosensor relies upon gold particles in much the same vein as your average pregnancy test. With a pregnancy test, gold particles turn the test window red because the particles are linked with an antigen that detects a certain hormone in the urine of a pregnant woman.

"Gold is the best medium," explains Chan, "because it's easy to see. It emits a very intense colour."

How the new process will work

Currently scientists can target the particular disease they are searching for by linking gold particles with DNA strands: when a sample containing the disease gene (ie. Malaria) is present, it clumps the gold particles, turning the sample blue. Rather than clumping the particles together, Zagorovsky immerses the gold particles in a DNA-based enzyme solution (DNA-zyme) that, when the disease gene is introduced, 'snip' the DNA from the gold particles, turning the sample red.

"It's like a pair of scissors," Zagorovsky explains, "and the target gene activates the scissors that cut the DNA links holding gold particles together."

The advantage is that far less of the gene needs to be present for the solution to show noticeable colour changes, amplifying detection. A single DNA-zyme can clip up to 600 "links" between the target genes.

Just a single drop from a biological sample such as saliva or blood can potentially be tested in parallel, so that multiple diseases can be tested for in one sitting.

But the team has also demonstrated that they are able to transform the testing solution into a powder, making it light and far easier to ship than solutions, which degrade over time. Powder can be stored for years at a time, and offers hope that the technology can be developed into efficient, cheap, over-the-counter tests for diseases such as HIV and malaria for developing countries, where access to portable diagnostics is a necessity.

"We've now put all the pieces together," says Chan.

EurekAlert

NEXT ON NEWS24 KENYAX

Read News24’s Comments Policy

Comment on this story
0 comments
Add your comment
Comment 0 characters remaining

Read more from our Users

Submitted by
William Korir
Mutua risks CORD isolation by snu...

Machakos Governor Alfred Mutua risks being isolated by the CORD coalition after missing an Okoa Kenya Referendum function but attending a visit by president Uhuru Kenyatta the following day. Read more...

Submitted by
William Korir
NGO board cancels licences of thr...

The NGO Board has canceled operating licences for three NGO's for links to terrorist activities. Read more...

Submitted by
Eugene Odanga
Wangechi performs live for the fi...

Rapper Wangechi will perform live for the first time since being involved in a grisly road accident. Read more...

Submitted by
William Korir
Raila woos Gusii leaders to suppo...

CORD leader Raila Odinga has wooed leaders from the Gusii community to support the Okoa Kenya referendum. Read more...

Submitted by
Victor Tinto
Kenyans don't trust Duale and Mut...

Kenyans do not trust leader of majority in the National Assembly Aden Duale, according to a poll. Read more...

Submitted by
Eugene Odanga
Gloria Muliro's ex husband moves ...

Gloria Muliro's ex husband pastor Eric Omba has delved into the world of film. Read more...