NUS researchers harness AI to identify cancer cells by their acidity

Novel technique paves the way for faster, inexpensive and accurate cancer diagnosis

The novel technique of using AI to quickly analyse cells for cancer diagnosis was developed by an NUS research team led by Professor Lim Chwee Teck (left). With him are two team members – Dr Jokhun Doorgesh Sharma (centre) and Dr Yuri Belotti (right).

Healthy and cancer cells can look similar under a microscope. One way of differentiating them is by examining the level of acidity, or pH level, inside the cells.

Tapping on this distinguishing characteristic, a research team from the National University of Singapore (NUS) has developed a technique that uses artificial intelligence (AI) to determine whether a single cell is healthy or cancerous by analysing its pH.

Each cancer test can be completed in under 35 minutes, and single cells can be classified with an accuracy rate of more than 95 per cent.

The research, led by Professor Lim Chwee Teck, Director of the Institute for Health Innovation & Technology (iHealthtech) at NUS, was first published in the journal APL Bioengineering on 16 March 2021.

“The ability to analyse single cells is one of the holy grails of health innovation for precision medicine or personalised therapy. Our proof-of-concept study demonstrates the potential of our technique to be used as a fast, inexpensive and accurate tool for cancer diagnosis,” said Prof Lim, who is also from the NUS Department of Biomedical Engineering.

Using AI for cancer detection

Current techniques for examining a single cell can induce toxic effects or even kill the cell. The approach developed by Prof Lim and his team, however, can distinguish between cells originating from normal and cancerous tissue, as well as among different types of cancer. Crucially, all of these can be achieved while keeping the cells alive.

The NUS team’s method relies on applying bromothymol blue – a pH-sensitive dye that changes colour according to the level of acidity of a solution – onto living cells. Due to its intracellular activity, each type of cell displays its own ‘fingerprint’ which consists of its own unique combination of red, green, and blue (RGB) components when illuminated.

Cancer cells have an altered pH compared to healthy cells, so they react differently to the dye, and this changes their RGB fingerprint.