Cell phone camera tracks bacteria

Using a Google smart phone, a commercially available cell-phone image sensor, and Lego building blocks, engineers at the California Institute of Technology (Pasadena, CA, USA) have developed a "smart" petri dish to image cell cultures.

According to Guoan Zheng, a graduate student in electrical engineering at Caltech, the lens-free ePetri microscopy imaging platform allows researchers to directly track the growth of cell or bacteria culture within an incubator.

A culture is placed on the image sensor, while the phone's LED screen is used as a scanning light source. As the sensor takes images of the culture, the information is transferred to a laptop, enabling the researchers to acquire and save images of the cells as they grow in real time.

In addition to simplifying medical diagnostic tests, the ePetri platform may be useful in various other areas, such as drug screening and the detection of toxic compounds.

Caltech biologist Michael Elowitz has used the ePetri system to observe embryonic stem cells. Stem cells in different parts of a petri dish often behave differently, changing into various types of other, more specialized cells.

Using a conventional microscope, a researcher is only able to focus on one region of the petri dish at a time. But by using the ePetri platform, Elowitz was able to follow the stem-cell changes over the entire surface of the device.

-- Posted by Vision Systems Design