Photostick enables the physical selection of single cells from large populations in diverse environments. The novel process entails photochemical immobilization of live cells with patterned illumination, followed by removal of unwanted cells with protease-mediated detachment.

Because the selection criteria are based on time-lapse microscopy, even weak and dynamic phenotypes may be selected. The technology is easily adaptable to many standard imaging platforms and operates well with conventional cell culture devices. Photostick therefore offers a straightforward, flexible solution to the problem of accurately screening mammalian cells.

How it works

The technology relies on a custom photochemical radical initiator that fixes live cells to plates upon illumination. By patterning light with either a digital micromirror device or a pair of scanning mirrors, Prof. Cohen's group has demonstrated that specific single cells can be retained with high efficiency following an accutase treatment to remove non-illuminated cells. Because the light-responsive crosslinker does not enter cells, screen isolates can be recovered and further propagated or sequenced.

Advantages

Since the approach relies on light for selection, the device is fully compatible with standard microscopes and transparent cell growth chambers. The screen has an enormous range of uses as the selection criteria are based on images and movies — essentially any phenotype that can be detected by microscopy can be screened.

Applications include gene function assays (e.g., siRNA libraries), protein engineering, and drug target screenings.