Building biological barcodes

The problem
Medical tests required to diagnose diseases need to be performed at specialized centres, causing long wait times and expensive costs. In addition, current analytical tools are limited to looking at only handful of the biomolecules that signal the onset of diseases, such as cancer.

The researcher
Michel Godin, an assistant professor in the Department of Physics at the U of O, dreams of making disease testing as easy as scanning a barcode. Godin is part of the Interdisciplinary Nanophysics Centre labs where he mixes physics, chemistry, and biology to engineer hand-held microfluidic devices for the health sciences.

The project
Microfluidic devices are the computer chips of the chemistry world. Medical lab technicians search for biomolecules associated with disease—also called biomarkers—the way you would do math on an abacus: one by one. Godin wants to design a device that can take less than a drop of blood, purify it, and identify the presence of hundreds of biomarkers within seconds. That kind of speed would resolve the earlier inconveniences of wait time and would also allow better statistics for analysis. The device would be smaller than your cell phone and potentially cheap enough to be used in developing countries. Bigger isn’t always better—at least when you’re talking about microfluidic devices.

The key
But how would Godin’s device tell the hundreds of biomarkers apart? Some microfluidic devices integrate ultra-sensitive detectors that push biomarkers through tiny nanoscopic tunnels (or nanopores) capable of detecting single molecules as they pass. However, detecting molecules and telling them apart are two very different processes. While a nanopore might be able to detect biomarkers, it can’t distinguish between those that signal disease and perfectly normal biomolecules. To identify them, Godin wants to create a DNA scaffold—a long chain of single-stranded DNA that would attach specific biomarkers to unique spots along the DNA chain. By threading the DNA through the nanopore, Godin could read what biomarkers are present in the blood—exactly like scanning a barcode.