Scientists develop cheap test for DNA biomarkers
US scientists have developed a cheap, highly accurate test that can be used to diagnose conditions by detecting protein biomarkers in subjects' DNA. The test could be as simple to use as a home pregnancy testing kit, according to the researchers from the Wyss Institute at Harvard University and Boston's Children's Hospital. In experiments, the method was used to detect prostate-specific antigen and to screen between different strains of the Dengue virus in less than an hour. It reduced false positives to nearly zero and achieved lab-quality sensitivity.

Scientists at the Wyss Institute at Harvard University and Boston Children’s Hospital have developed a cheap, sensitive, and highly accurate way of detecting protein biomarkers. The technology may very well revolutionize diagnostics, disease monitoring, and help stop the spread of infectious pathogens. The nanoswitch-linked immunosorbent assay (NLISA) has the potential to be as simple to use as self-administered pregnancy tests but with nearly laboratory-level of accuracy.

NLISA screens for specially prepared DNA strands that change shape in the presence of a protein biomarker. The DNA strands have multiple small proteins that bind to the target proteins, and as they bind, they pull on the rest of the DNA strand, changing its shape. Electrophoresis is then used to pull on the DNA strands, some of which move faster than others depending on whether they’ve been bent out of their original shape or not. Moreover, while the dragging is going something called “kinetic proofreading” is administered to the DNA strands, shaking loose any imperfect connections that may lead to false positives.

The technology, just described in Proceedings of the National Academy of Sciences, was used to detect prostate-specific antigen (PSA) at high sensitivity and to screen between different strains of the Dengue virus in less than an hour. False positives were reduced to nearly zero while the sensitivity was lab quality.

Here’s a quick animation that explains the workings of the NLISA technology:

Study in PNAS: Nanoswitch-linked immunosorbent assay (NLISA) for fast, sensitive, and specific protein detection…

Via: Wyss Institute…