Anna Huttenlocher, University of Wisconsin, Madison
Studying the migration of leukocytes along chemotactic gradients.
Gradients are best controlled with fluid flow, but fluid flow disperses secreted factors that may be important in cell-cell interactions.
Huttenlocher collaborated with an engineer at her university, David Beebe, to create what he calls "the world's simplest microfluidic device." It's less than a centimeter long, composed only of three layers of polydimethylsiloxane (PDMS) plastic and polyester membranes. Near one end is a well covered by a membrane (the sink); near the other, atop another membrane, is a large opening leading to another well (the source)....
Loading cells into the device without disturbing the gradient was tricky, Huttenlocher says, until she tried first introducing a collagen gel into the channel and letting it solidify to give the cells a 3-D matrix to move through.
The duo serialized a subsequent iteration, lining up several channels in parallel on a glass slide to run multiple conditions simultaneously. "You can actually zoom through with a microscope, going from one channel to the next in an automated way," Huttenlocher says. They also further improved ease of cell loading, and are now commercializing a version of the system through BellBrook Labs.
The group's prototype can be made for under $10; the cost of the commercialized device isn't yet set.