Coming, super sensitive test to detect cancers, HIV

A new technique developed by a team of chemists at Stanford University has shown promise to be thousands of times more sensitive than current techniques to diagnose diseases -- whether it is a cancer or a virus like HIV.

Found effective in laboratory experiments, the technique, described in the journal ACS Central Science, is now being put to test in real-world clinical trials.

When a disease begins growing in the body, the immune system responds by producing antibodies.

Fishing these antibodies or related biomarkers out of the blood is one way that scientists infer the presence of a disease.

This involves designing a molecule that the biomarker will bind to, and which is adorned with an identifying "flag." Through a series of specialized chemical reactions, known as an immunoassay, researchers can isolate that flag, and the biomarker bound to it, to provide a proxy measurement of the disease.

The new technique, developed in the lab of Carolyn Bertozzi, professor of chemistry at Stanford, augments this standard procedure with powerful DNA screening technology.

In this case, the chemists 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 detections.

The researchers tested their technique, with its signature DNA flag, against four commercially available tests for a biomarker for thyroid cancer.

It outperformed the sensitivity of all of them, by at least 800 times, and as much as 10,000 times.

By detecting the biomarkers of disease at lower concentrations, physicians could theoretically catch diseases far earlier in their progression.

"The thyroid cancer test has historically been a fairly challenging immunoassay, because it produces a lot of false positives and false negatives, so it wasn't clear if our test would have an advantage," said study co-author Peter Robinson.

"We suspected ours would be more sensitive, but we were pleasantly surprised by the magnitude," Robinson noted.

Based on the success of the thyroid screening, the group has won a few grants to advance the technique into clinical trials for screening other diseases including HIV.