Infectious diseases remain to be the leading cause of global mortality in addition to respiratory infections. In detecting the presence of pathogens, the conventional method uses amplification assays based on the detection and replication of protein and nucleic acids such as DNA and RNA. This is widely used during pandemics such as COVID-19.
Despite the accuracy of this method, the assays involve lengthy protocols, which make it difficult to detect the infection at the point of need. Because of this, a rapid, large-scale diagnostic material for the early detection of such diseases is needed as it is not currently available.
New Technique with Rapid Results
In response to this challenge, a group of scientists developed an all-in-one detection platform that could deliver test results in just 13 minutes. Led by McGill University Professor of Bioengineering Sara Mahshid, they created the diagnostic tool QolorEX using nanoparticle and artificial intelligence in collaboration with experts from the Jewish General Hospital and Research Institute of the McGill University Health Centre (RI-MUHC).
The team aims to develop a portable, low-cost detection platform that can provide practical clinical results. They plan to use this to respond to future pandemics requiring convenient tools at home, in low-resource areas, and in communal environments.
The detection method includes transferring saliva samples into a microfluid device. Artificial intelligence is applied to take microscopic images of the sample automatically. The captured images will be sent to a smartphone application that interprets the data into a test result.
QolorEX uses nanoparticles and an automated system where microfluidics is coupled with plasmonic hot electron injection to speed up colorimetric sensing. Various amplification assays were used to identify pathogens in human saliva samples. The DNA and RNA amplification can also distinguish between viral groups and subtypes.
After testing the platform's effectiveness, the scientists found out that it has a 95% accuracy rate, comparable to the conventional quantitative polymerase chain reaction (PCR) test used for COVID-19. It was a significant tool for monitoring emerging pathogens such as viruses and bacteria. Because of its accessible feature, more tests can be performed, and more lives can be saved by early diagnosis, preventing the spread of respiratory diseases globally.
What is Nucleic Acid Amplification?
Nucleic acid amplification tests (NAAT) detect a specific nucleic acid and protein sequence of a species or subspecies of the organism. It involves taking small amounts of DNA or RNA, replicating them many times, and detecting minute traces of an organism in a sample. This method is useful in detecting organisms that are hard to culture using other techniques, such as viruses, fungi, and bacteria.
There are various forms of NAAT methods currently in use today, including reverse transcription polymerase chain reaction (RT-PCR), strand displacement amplification (SDA), and transcription-mediated amplification (TMA). Medical authorities have authorized the use of NAATs in various settings, such as laboratories or point-of-care settings.
NAAT is an important molecular tool in various industries, such as gene cloning, diagnosing infectious diseases, and developing clinical drugs. During the COVID-19 pandemic, NAAT methods were widely used to detect SARS-CoV-2.
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