Recent studies have shown that even a single mutation can make the difference between success or failure of treatment. Now researchers have developed a new technology that can detect even a single DNA mutation that can help diagnose and treat diseases such as tuberculosis or cancer. It seems that these small changes in DNA structure may be due to antibiotic resistance.
Lead author Georg Seelig, a University of Washington assistant professor of electrical engineering and of computer science and engineering, said that they improved previous approaches because their new method requires no complicated reactions and enzymes, they are just using DNA. He added that the the parameters can be modified (temperature and environment ) which means it is suitable for many diagnostic applications.
DNA is actually a nucleic acid that carries the genetic information and is composed of several base pairs. A simple modification (mutations, deletions, insertions) in one of these base pairs is sufficient to trigger important biological consequences. These changes explain why certain diseases occur or why antibiotic resistance appears. Tuberculosis, for example, is an infectious disease caused by Mycobacterium tuberculosis (Gram-positive battery that requires oxygen for survival) is a disease sometimes difficult to treat because, over time, several strains resistant to treatment occured. This resistance to antibiotics is due to small changes in a single gene. Seelig explained that if a person is resistant to treatment, this is due to the presence of a mutation in DNA.
Now researchers can detect these mutations in advance. Seelig and a team of researchers have developed a method that can detect mutations in a single base pair of DNA. This new method allows researchers to look more in detail at variations in long sequences up to 200 base pairs (the current methods can only detect mutations in sequences up to 20 base pairs). Zhang, an assistant professor of bioengineering at Rice University, said: “In terms of specificity, our research suggests that we can do quadratically better, meaning that whatever the best level of specificity, our best will be that number squared.”
This new method involves the use of test probes that bind to the DNA that supposedly contains a mutation. Researchers must create a sequence complementary to the DNA double helix, then mix both sequences in a test tube, where the two base pairs should match up if they are intact. The test probe is designed to emit a fluorescent glow if there is a match between it and the target. If it does not emit fluorescence it means that there is a mutation in the DNA.
For further reading on Tuberculosis treatment : New Drug Candidate for Tuberculosis