A team in Japan has created what it describes as the world's first DNA aptamer capable of binding neurofilament light chain (NfL), the protein that leaks out of damaged nerve fibers and turns up in cerebrospinal fluid and, eventually, the bloodstream. Aptamers are short, single-stranded synthetic DNA molecules that fold into shapes which latch onto a specific target. According to the researchers, this one binds NfL with an affinity comparable to commercially available antibodies.
NfL matters because neurodegeneration in Alzheimer's disease starts years before memory problems become obvious, and measuring nerve cell injury directly is one of the few ways to see that process underway. Current tests rely on antibodies, which are expensive to produce and can vary between manufacturing batches. Synthetic DNA aptamers are cheaper and can be made to a consistent standard, which is what makes them appealing as the recognition element in biosensors and blood-based diagnostic tests.
The work was led by Associate Professor Kaori Tsukakoshi of the Department of Chemistry at Tokyo University of Science, with master's student Miyu Matsumoto and Distinguished Professor Kazunori Ikebukuro of the Department of Biotechnology at Tokyo University of Agriculture and Technology. It appeared online on December 16, 2025, and was published in Volume 796 of Biochemical and Biophysical Research Communications on January 18, 2026, as part of a joint UK-Japan project supported by AMED-SICORP.
Tsukakoshi frames the result as a starting point rather than a finished test, noting that NfL rises in the blood across a range of neurodegenerative diseases and that the aptamer is expected to find applications such as tracking the progression of Alzheimer's. Turning a well-behaved binding molecule into a clinical assay is a separate stretch of work, but a low-cost, reproducible alternative to antibodies would ease one of the practical bottlenecks in scaling blood tests for dementia.