MIT Creates 1st 3-D Image of a Living Cell

A new imaging technique developed at MIT's Laser Biomedical Research Center has allowed scientists to create the first 3D images of a living cell, using a method similar to the X-ray CT scans doctors use to see inside the body.

The technique could be used to produce the most detailed images yet of what goes on inside a living cell without the help of fluorescent markers or other externally added contrast agents, said Michael Feld, director of MIT's George R. Harrison Spectroscopy Laboratory and a professor of physics.

The researchers based their technique on the same concept used to create three-dimensional CT (computed tomography) images of the human body, which allow doctors to diagnose and treat medical conditions. CT images are generated by combining a series of two-dimensional X-ray images taken as the X-ray source rotates around the object.

Cells don't absorb much visible light, so the researchers instead created their images by taking advantage of a property known as refractive index. Every material has a well-defined refractive index, which is a measure of how much the speed of light is reduced as it passes through the material. The higher the index, the slower the light travels.

To create a 3D image, the researchers combined 100 two-dimensional images taken from different angles. The resulting images are essentially 3D maps of the refractive index of the cell's organelles. The entire process took about 10 seconds, but the researchers recently reduced this time to 0.1 seconds.

One major advantage of the new technique is that it can be used to study live cells without any preparation With essentially all other 3D imaging techniques, the samples must be fixed with chemicals, frozen, stained with dyes, metalized or otherwise processed to provide detailed structural information.

Posted by Casey Kazan.

MIT Link

Comments

[T.R.M.Ekambaram]

congrats

[alloy analyzer]

Hi,
Very good post.One key advantage of the new technique is that it can be used to study live cells without any preparation.When you fix the cells, you can't look at their movements, and when you add external contrast agents you can never be sure that you haven't somehow interfered with normal cellular function.