Hypersensitive analysis
The new technique will detect cancer by a single molecule
Sergey Kolenov, Hi-tech+
Malignant cells are characterized by certain mutations that allow them to multiply rapidly and avoid the attention of the immune system. Many of them manifest themselves in microRNAs – small molecules that perform regulatory functions.
Researchers consider the microRNA released from cells to be an ideal biomarker for detecting cancer. For example, the analysis of these molecules is often used in liquid biopsy, an experimental diagnosis of cancer based on a small blood sample.
Researchers from the University of Illinois, whose work is described in the press release Single-molecule detection of cancer markers brings liquid biopsy closer to clinic, presented a new method for capturing and counting cancer-associated microRNAs. The authors called it photon resonance absorption microscopy (FRAM).
According to scientists, the technique combines sensitivity and selectivity, that is, it detects even small concentrations of malignant microRNAs without reacting to normal ones.
This was achieved by combining molecular probes with a sensor on a photonic crystal. Each probe is designed to interact with a specific microRNA. Having come into contact with it, the molecule drops the protective cap and binds to the sensor. As a result, a signal specific to different types of microRNAs is generated.
FRAM is sensitive to a much lower concentration of target molecules than, for example, fluorescence and other traditional methods. This makes it possible not only to diagnose the disease, but also to monitor its development and reaction to therapy in the future. In addition, the diagnosis is much faster than many other methods – a couple of hours is enough.
FRAM has already been successfully tested on two microRNA markers of prostate cancer. According to the authors, it can be adapted for other oncological diseases. They hope that in the near future FRAM will become the basis for a simple diagnostic device that can be installed in many clinics.
Article by Canady et al. Digital-resolution detection of microRNA with single-base selectivity by photonic resonator absorption microscopy is published in PNAS – VM.
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