Snapshooting a Cell's Life

British scientists have developed a new, extremely fast, high-resolution infrared imaging technique, that can photograph living cells in less than one second, and tested it on human ovarian cancer cells.

This technique could bring an important amount of information on cell development and the way that cancer drugs work.

Chris Phillips and his team at Imperial College London have developed this new method, which, in a fraction of a second, can take 2D images of living cells, without affecting them.

They combined a purpose-built pulsed IR laser source with a charge-coupled device camera, similar to the mechanism of a digital camera, and they managed to take pictures 10 times faster than the current IR spectroscopic imaging methods do.

This IR source generates very short pulses, almost 100 pulses a second, which limit the illumination levels under cell phototoxicity limits.

Basically, moving specimens can be photographed just like in conventional flash photography.

To test this technique, the team took a series of single shot pictures of live human ovarian cancer cells, at a wavelength that allowed a clear contrast between the nucleus and the cytoplasm of single cells during the multiplication process.

“This seems to be very interesting in that it's using ultrafast laser technology to produce microscopy images, which gives the advantage of much improved sensitivity in relation to methods that have been previously used for infrared microscopy,” said Neil Hunt, an expert in IR spectroscopy at the University of Strathclyde, Glasgow, UK.

Before this new technique, any attempts to 'freeze' cells like this would have required long illumination times, and the problem is that light causes the cells to move away from it and can even destroy them.

Phillips says that “because you can do it so quickly, you can freeze the action in living things, and because you have so much more light signal, you can get right inside the cells to take chemical maps.”

Infrared spectroscopy of cell images is currently used in cancer research and in forensic science, still taking pictures of samples can take up to 12 hours, the Royal Society of Chemistry reports.

So the new technique will surely be more helpful and definitely much faster, and cancer researchers could use the time gain.

To start with, the scientists could work with oncologists and track the internal chemistry of cells, and the population of cells being treated with cancer drugs to help understand how the drugs work.

Then, they could take a sample of tissue, normally used for a biopsy, and image it with their camera – which could allow measurements of the chemicals in the cells, and make the difference between cancerous and healthy tissue.

Phillips says that in this field, the new technique “might make its biggest and earliest impact.”