Rapid, Simple, Inexpensive Diagnostic Tests Developed Using DNA
By LabMedica International staff writers Posted on 12 Oct 2015 |
Image: Schematic representation of DNA-based electrochemical sensor (Photo courtesy of University of Montreal).
A highly selective DNA-based electrochemical sensor that utilizes steric hindrance effects to signal the presence of large macromolecules in a single-step procedure has been developed.
Electrochemical test's sensing principle may be generalized to many different targets, leading to inexpensive devices that could detect dozens of disease markers in less than five minutes. A large macromolecule, such as a protein, when bound to a signaling DNA strand generates steric hindrance effects, which limits the ability of this DNA to hybridize to a surface-attached complementary strand.
Scientists at the University of Montreal (QC, Canada) and their Italian colleagues used DNA molecules to developed rapid, inexpensive medical diagnostic tests that take only a few minutes to perform. Their findings, may aid efforts to build point-of-care devices for quick medical diagnosis of various diseases ranging from cancer, allergies, autoimmune diseases, sexually transmitted diseases (STDs), and many others.
They demonstrated that the efficiency of hybridization of this signaling DNA was inversely correlated with the size of the molecule attached to it, following a semi-logarithmic relationship. Using this steric hindrance hybridization assay in an electrochemical format (eSHHA), they demonstrated the multiplexed, quantitative, one-step detection of various macromolecules in the low nanomolar range, in less than 10 minutes directly in whole blood. The sensing principle was straightforward as the diagnostically relevant protein (green or red), if present, binds to an electro-active DNA strand, and limits the ability of this DNA to hybridize to its complementary strand located on the surface of a gold electrode.
Sahar Mashid, PhD, the first author of the study, said, “While working on the first generation of these DNA-base tests, we realized that proteins, despite their small size are big enough to run into each other and create steric effect (or traffic) at the surface of a sensor, which drastically reduced the signal of our tests. Instead of having to fight this basic repulsion effect, we instead decided to embrace this force and build a novel signaling mechanism, which detects steric effects when a protein marker binds to the DNA test.” The study was published online on September 4, 2015, in the Journal of the American Chemical Society.
Related Links:
University of Montreal
Electrochemical test's sensing principle may be generalized to many different targets, leading to inexpensive devices that could detect dozens of disease markers in less than five minutes. A large macromolecule, such as a protein, when bound to a signaling DNA strand generates steric hindrance effects, which limits the ability of this DNA to hybridize to a surface-attached complementary strand.
Scientists at the University of Montreal (QC, Canada) and their Italian colleagues used DNA molecules to developed rapid, inexpensive medical diagnostic tests that take only a few minutes to perform. Their findings, may aid efforts to build point-of-care devices for quick medical diagnosis of various diseases ranging from cancer, allergies, autoimmune diseases, sexually transmitted diseases (STDs), and many others.
They demonstrated that the efficiency of hybridization of this signaling DNA was inversely correlated with the size of the molecule attached to it, following a semi-logarithmic relationship. Using this steric hindrance hybridization assay in an electrochemical format (eSHHA), they demonstrated the multiplexed, quantitative, one-step detection of various macromolecules in the low nanomolar range, in less than 10 minutes directly in whole blood. The sensing principle was straightforward as the diagnostically relevant protein (green or red), if present, binds to an electro-active DNA strand, and limits the ability of this DNA to hybridize to its complementary strand located on the surface of a gold electrode.
Sahar Mashid, PhD, the first author of the study, said, “While working on the first generation of these DNA-base tests, we realized that proteins, despite their small size are big enough to run into each other and create steric effect (or traffic) at the surface of a sensor, which drastically reduced the signal of our tests. Instead of having to fight this basic repulsion effect, we instead decided to embrace this force and build a novel signaling mechanism, which detects steric effects when a protein marker binds to the DNA test.” The study was published online on September 4, 2015, in the Journal of the American Chemical Society.
Related Links:
University of Montreal
Latest Clinical Chem. News
- 3D Printed Point-Of-Care Mass Spectrometer Outperforms State-Of-The-Art Models
- POC Biomedical Test Spins Water Droplet Using Sound Waves for Cancer Detection
- Highly Reliable Cell-Based Assay Enables Accurate Diagnosis of Endocrine Diseases
- New Blood Testing Method Detects Potent Opioids in Under Three Minutes
- Wireless Hepatitis B Test Kit Completes Screening and Data Collection in One Step
- Pain-Free, Low-Cost, Sensitive, Radiation-Free Device Detects Breast Cancer in Urine
- Spit Test Detects Breast Cancer in Five Seconds
- Electrochemical Sensors with Next-Generation Coating Advances Precision Diagnostics at POC
- First-Of-Its-Kind Handheld Device Accurately Detects Fentanyl in Urine within Seconds
- New Fluorescent Sensor Array Lights up Alzheimer’s-Related Proteins for Earlier Detection
- Automated Mass Spectrometry-Based Clinical Analyzer Could Transform Lab Testing
- Highly Sensitive pH Sensor to Aid Detection of Cancers and Vector-Borne Viruses
- Non-Invasive Sensor Monitors Changes in Saliva Compositions to Rapidly Diagnose Diabetes
- Breakthrough Immunoassays to Aid in Risk Assessment of Preeclampsia
- Urine Test for Monitoring Changes in Kidney Health Markers Can Predict New-Onset Heart Failure
- AACC Releases Comprehensive Diabetes Testing Guidelines