Research Highlight

Optical trap to detect cancer cells

doi:10.1038/nindia.2016.42 Published online 28 March 2016

Researchers have developed an optical method that uses laser light and an inverted microscope to distinguish malignant cancer cells from less-malignant ones by measuring the cell–cell adhesion time1. This method is potentially useful for selecting cancer cells from a mix of cancer and healthy cells, and hence could be an efficient diagnostic tool.

Current techniques for detecting cancers employ time-consuming, invasive tests. To devise a non-invasive method for detecting cancer, the researchers created an optical trap by coupling laser light to an inverted microscope. Using this trap, they then measured the cell–cell adhesion times of malignant cancer cells isolated from specific human and rat brain tumour cell lines.

Cell–cell adhesion times were determined by trapping a randomly selected live cancer cell, bringing it close to another cancer cell for various times, and then pulling it away.

Undifferentiated cancer cells had longer cell–cell adhesion times than differentiated cancer cells: well-differentiated, less-malignant cancer cells exhibited cell–cell adhesion times between 5 and 7 seconds, whereas poorly differentiated, more-malignant cancer cells had cell–cell adhesion times in the range 20–25 seconds.

“This method has an edge over conventional tissue-based cancer diagnosis as it doesn’t need any lengthy biochemical procedures for detecting and distinguishing cancer cells,” says Uma Ladiwala, one of the researchers.


1. Pradhan, M. et al. Optically trapping tumor cells to assess differentiation and prognosis of cancers.Biomed. Optics Express 7, 943–948 (2016)