The ePetri dish: Android and Lego improve century-old tool

Caltech engineers have designed a new petri dish that can photograph growing cells continuously while they're being incubated. No microscopes, minimal contamination. With video.
Written by Janet Fang, Contributor

Caltech engineers have built a smart petri dish that can image the growth of cells continuously while they incubate. The new tech simplifies medical diagnoses by allowing scientists to watch cells grow in real time with fewer contaminations.

The petri dish has been helping scientists grow cells and identify bacterial infections like tuberculosis since the late 1800s. In order to grow, the cells being cultured usually need to be placed in an incubator. Then later, they can be examined under a microscope, and then put back, and then again.

The new ePetri does away with bulky microscopes, recording cell growth continuously with its small, lens-free microscopy imaging platform while in the incubator.

According to team leader Guoan Zheng of Caltech, data from the ePetri dish automatically transfers to a computer outside of the incubator by a cable connection. “This technology can significantly streamline and improve cell culture experiments by cutting down on human labor and contamination risks," Zheng explains.

The platform prototype was built using a Google Nexus S smartphone, an image sensor chip found in cellphone cameras, and Lego building blocks.

  1. The culture is placed on the image sensor chip (pictured).
  2. The Android is placed over it on Lego scaffolding (pictured, left). The phone’s LED screen is used as a light source like in a scanner, Wired explains, brightening up the cell and allowing an image to be captured by the sensor.
  3. The whole thing is placed in an incubator with a wire running from the chip to a laptop outside.
  4. As the image sensor takes pictures of the culture, that info is sent to the laptop, giving the researchers images of the cells as they’re growing in real time.

You can watch a video here.

"With ePetri, you can survey the entire field at once, but still maintain the ability to 'zoom in' to any cells of interest," says coauthor Caltech’s Michael Elowitz. "In this regard, perhaps it's a bit like an episode of CSI where they zoom in on what would otherwise be unresolvable details in a photograph."

Some other uses in addition to desktop diagnostics include screening drugs, detecting toxic compounds, and providing imaging tech for lab-on-a-chip tools.

The work was published in the Proceedings of the National Academy of Sciences yesterday.

Images: Guoan Zheng / Caltech

This post was originally published on Smartplanet.com

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