FISH-ing for cancer just got easier

Fluorescence in situ hybridization (FISH) can detect chromosomal mutations that cause cancer, but the technique can take days to perform and cost hundreds of dollars. Consequently, the method is not yet widely used in clinical settings. However, researchers from the University of Alberta and from Cross Cancer Institute, both in Edmonton, Canada, integrated the technique into a microfluidics chip, enabling the test to run in just hours at a cost of only tens of dollars.

This fluorescence image shows a microchannel within a microfluidics chip after FISH was performed.

Additionally, the chip is the size of a microscope slide, and it can be combined with peripheral equipment half the size of a shoebox for a totally automated process, whereas FISH ordinarily requires bulky instruments and costly manual analysis by a technical expert. The fluorescent probes travel through tiny channels that contain the cells, permeate the cells and bind to chromosomes, enabling visualization of chromosomes, so that clinicians can count them or detect cancer-promoting breaks and reattachments.

“FISH on a chip is well-suited to detection of circulating cancer cells, offering the possibility for a less invasive testing strategy and for detecting usually rare metastatic cancer cells that have escaped from a solid tumor mass,” said principal investigator Linda M. Pilarski. The technique also works well with blood cancers, and it can be used with solid tumors. In addition, it can help doctors determine prognoses and treatment options.

FISH on the chip ran faster and required one-tenth the number of probes needed without the chip, and the researchers could differentiate between malignant and benign cells, as reported in the June issue of IET Nanobiotechnology.

Pilarski said that the researchers would like to further optimize FISH on a chip by improving cell processing and using probes and optical detection methods. However, their prototype shows that such a device can rapidly become available for routine clinical testing, she said.