User:
Anna Huttenlocher, University of Wisconsin, Madison
Project:
Studying the migration of leukocytes along chemotactic gradients.
Problem:
Gradients are best controlled with fluid flow, but fluid flow disperses secreted factors that may be important in cell-cell interactions.
Solution:
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). A 3-mm channel in the bottom layer of PDMS connects the two. Placing buffer in the sink and adding chemoattractants to the source creates the gradient.
Loading cells into the device without disturbing the gradient was tricky, Huttenlocher says, until she tried first introducing a collagen ...
