New Test Procedure Offers Earlier Detection of Cancer, HIV

DNA screening technology up to 10,000 times more sensitive than current tests for cancer and HIV.

Stanford chemists have developed a new technique that is significantly more sensitive than current tests to help detect diseases such as cancer or HIV earlier.

The standard procedure used for catching cancer or infectious diseases involve removing the antibodies or biomarkers from the blood to determine the presence of disease.

The procedure uses a molecule designed to allow the biomarker to bind to it and then identifying it with a “flag.” Researchers can isolate this flag through a series of specialized chemical reactions in order to get a proxy measurement of the disease.

In the current study, published in the journal ACS Central Science, researchers used a powerful DNA screening technology in addition to the standard procedure, but instead replaced the standard flag with a short strand of DNA. This can be teased out of the sample by using sensitive DNA isolation technologies.

“This is spiritually related to a basic science tool we were developing to detect protein modifications, but we realized that the core principles were pretty straightforward and that the approach might be better served as a diagnostic tool,” said study co-author Peter Robinson.

During the study, researchers used the signature DNA flag against 4 FDA-approved tests for a thyroid cancer biomarker.

The results of the study showed that the technique was at least 800 times more sensitive, and as much as 10,000 times more sensitive.

“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,” Robinson said. “We suspected ours would be more sensitive, but we were pleasantly surprised by the magnitude.”

Carolyn Bertozzi, a professor of chemistry at Stanford whose lab the new technique was developed in, has primarily focused on putting basic research to use in a clinical setting. Currently, Bertozzi’s technique is being tested in real world clinical trials.

Since the successful thyroid screening, the researchers have won a few grants to help advance the technique in clinical trials, 1 of which that will help evaluate the technique as a screening tool for HIV.

Additionally, researchers are studying tests for type 1 diabetes that can help detect the disease earlier.

“Many of our collaborators are excited that the test can be readily deployed in their lab,” said co-author Cheng-ting "Jason" Tsai. “In contrast to many new diagnostic techniques, this test is performed on pre-existing machines that most clinical labs are already familiar with.”