Yong-Ak (Rafael) Song, associate professor of mechanical and biomedical engineering, is developing a DNA detection method that could prove to be less time-consuming in tracing biomolecules of the coronavirus.
The method known as electrokinetic preconcentration technique can increase the concentration of nucleic acid molecules of a sample inside a microfluidic channel and make them easier to detect.
Every detection method for any nucleic acid requires the target molecule be amplified to higher levels.
Current tests required to detect small amounts of DNA or RNA, such as is the case in viruses, always require an amplification method to allow for instruments to determine the presence of a specific viral DNA or RNA. In the case of COVID-19, the medical community has opted to use Polymerase Chain Reaction, or PCR, as the gold standard to amplify the presence of the viral RNA.
Techniques such as PCR or isothermal amplification, require running a constant temperature at 65 ℃ to amplify the target DNA or RNA.
“But both amplification methods require special reagents and primers, and it takes time, at least 30 minutes for each. So we thought why can’t we use this electro-kinetic pre-concentration technique to achieve that,” he said.
The method his group has developed is different to other amplification methods in that it doesn’t multiply molecules of any given target DNA. Rather it concentrates existing molecules of a sample inside a microfluidic channel so that they can be detected more easily with their enhanced concentration.
PCR, the gold standard of molecule bolstering techniques, and other similar analysis methods are riddled with certain issues that the medical community has mitigated but not altogether eliminated.
Firstly, thermal-based technique requires prior knowledge of the DNA or RNA that a test is attempting to detect, such that the reagents and primers can be applied accordingly to amplify the molecules. This step is critical in tracing a specific sample but could leave other DNA or RNA, such as other viruses, undetected.
Secondly, the aggressive amplification of rapidly making millions to billions of copies of a specific DNA sample could skew results. In this case even the smallest trace amounts of a DNA could be multiplied and produce misleading results.
Song’s method does no such amplification. Instead, it runs a small electric current through a microfluidic channel, or a tube, that drives the molecules towards a membrane that traps all the DNA in a sample in one specific spot, thereby increasing the concentration locally. That spot can then be used to detect a range of different DNA’s without needing to use other samples.
“Essentially, we’re squeezing the DNA together to one tiny spot. This way we increase the concentration of the DNA or RNA in the channel where the sensor is located. This way we can easily detect its presence without resorting to a highly sensitive detection method. Even a standard smartphone camera with an appropriate filter could be used for detection,” he said.
The method could cut down on time and cost needed to test for any nucleic acid and help the scientific and medical community detect with more accuracy a wider range of diseases.
The team is currently working to improve the technique to be able to selectively concentrate a specific target with a higher concentration factor. A group of students at NYUAD is also involved in this research.
Once fully developed, the invention could be used at home for a quick pre-screening, which would allow for more testing on a larger scale and reduces the number of cases until a safe vaccine has been developed and distributed. The impact of the device extends beyond the original purpose of SARS-CoV-2 detection, and can be utilised to detect the presence of other known pathogens.
Song’s research is among ten NYUAD COVID-19 research grants awarded to faculty across a range of disciplines designed to support academic research with the potential to mitigate the impact of COVID-19.
Song has also been awarded the Applied Research and Development programme ‘SWARD’ grant by Sandooq Al Watan – the national initiative launched by prominent Emirati businessmen to support research projects for the post-oil era.
