Biological Microtechnology and BioMEMS Group :: Professor Joel Voldman

Home News Research Publications People Join the Group Contact Password Protected Area


Image-based cell sorting

We have been creating systems to allow facile sorting of cells imaged with microscopy. The goal is to be able to screen cells for complex phenotypes, where the information content resides in spatial or dynamic information.

Electrical Techniques

One of our technologies uses large arrays of addressable electrical traps that use dielectrophoresis (DEP) to hold, image, and then sort many cells at once. Crucially to the technologies success, we have developed an efficient scheme to address many traps (up to 1000's) using only passive electronics (e.g., no transistors). To do this, we have developed a row-column addressing scheme to requires control electrodes only for each row and column, rather than each trap.


We microfabricate our traps here at MIT. At left we show an example of sorting of HL-60s. Here we have randomly loaded green- and orange-labeled cells into a 4x4 trap array, imaged them, and then sorted the green cells from the array. We are currently scaling up these arrays to a size appropriate for performing real-world assays.




We have also made DEP traps that use a combination of hydrodynamic and electrical forces to organize and sort particles. These traps, an SEM of which is shown at right, use a polymer weir to hydrodynamically trap particles, and use electrodes at the bottom of the weir to exert repulsive DEP forces to sort particles. With such a system, one can not only sort desired particles, but also load prescribed arrays of particles (shown below).

Optical Techniques

We can also sort cells using optical forces. We have developed an optical cell sorting approach that uses a laser to exert a force on particles akin to a laser firehose, where the scattering force dominates. By combining this approach with an array of microwells, we have created a large-scale sorting system capable of imaging and sorting 1,000’s of cells. At right is a schematic of the device. Below is a scan of the entire 10,000-site array, showing how cells can be imaged and then sorted. We have also performed high-resolution image-based sorts based upon fluorescence localization using this technology.


For more information on image-based cell sorting, see our Publications, our 2006-07 RLE progress report, and the MEMS section of the MTL Annual Research Report.




Home | News | Research | Publications | People | Join The Group | Contact © Massachusetts Institute of Technology
Link: RLE at MIT Link: MIT