Researchers at the University of Illinois, US have developed a method to detect microRNA cancer biomarkers with single-molecule resolution.

The technique, Photonic Resonator Absorption Microscopy (PRAM), captures and counts cancer-associated microRNAs, known biomarkers for prostate cancer.

The research team, led by University of Illinois professor Brian Cunningham, collaborated with Moffitt Cancer Center professor Manish Kohli to test PRAM on two microRNAs.

By combining a molecular probe and a photonic sensor, PRAM maintains both sensitivity and selectivity while detecting the presence of cancer biomarkers in a patient’s serum.

Brian Cunningham said: “Cancer cells contain gene mutations that enable them to proliferate out of control and to evade the immune system and some of those mutations turn up in microRNAs.”

The probe has a protective cap that detaches when it detects and binds to the target biomarker.

By binding to a photonic sensor, the exposed end of the probe produces a signal visible through a microscope, enabling the researchers to detect cancer markers.

This fast, inexpensive technique can detect even small quantities of biomarkers, researchers claim.

Cunningham said: “This advance demonstrates that it is possible to have an inexpensive and routine method that is sensitive enough to require only a droplet of blood.

“The results of the test might tell a physician whether a regimen of chemotherapy is working, whether a person’s cancer is developing a new mutation that would make it resistant to a drug or whether a person who had been previously treated for cancer might be having a remission.”

Researchers claim the PRAM approach could be adapted to different microRNAs or other biomarkers and is compatible with current microscope platforms.