A new ultra-sensitive test designed to detect diseases including HIV and cancer may prove 10,000 times more effective than current diagnostic tools, Stanford scientists say.
When a disease—whether it is a cancer or a virus like HIV—begins growing in the body, the immune system responds by producing antibodies. Fishing these antibodies or related bio-markers out of the blood is one way that scientists infer the presence of a disease. This involves designing a molecule that the bio-marker will bind to, and which is adorned with an identifying “flag.”
Through a series of specialised chemical reactions, known as an immuno-assay, researchers can isolate that flag, and the bio-marker bound to it, to provide a proxy measurement of the disease. The new technique, developed in the lab of Carolyn Bertozzi, a professor of chemistry at Stanford University in US, augments this standard procedure with powerful DNA screening technology. The chemists have replaced the standard flag with a short strand of DNA, which can then be teased out of the sample using DNA isolation technologies that are far more sensitive than those possible for traditional antibody detection.
This is spiritually related to a basic science tool we were developing to detect protein modifications, but we realised that the core principles were pretty straightforward and that the approach might be better served as a diagnostic tool.Peter Robinson, a graduate student in Bertozzi’s group