Shear-free chemotaxis: potential room for improvements

One major problem that we faced with our current shear-free chemotaxis system is the lack of high image quality.  Since the silicon-nitride (SiN )grid is 100 um away from the coverslip surface on which the cells migrate, the out-of-focused SiN grid blurs the image.  This makes cell tracking much harder.

An example of a movie of the shear-free chemotaxis: [MOVIE] Tracking shearfree chemotaxis 22 cells compressed (2012-10-09).

As we can see it is hard to make out where the cells are sometimes.

22 cells were randomly selected to have their migratory trajectories displayed.  We did not show all 400 trajectories because it would overcrowd the movie.

One solution is to have the cells migrating directly on the hybrid membrane.  There are a few advantages…. 1. We no longer get the out-of-focus blurring of the SiN grid.  2. The SiN can even be used as a cell displacement reference point.  3.  The cells can see the gradient/molecules more directly.  However, this strategy would requires us to redesign the shear-free chemotaxis system…. because to have the researchers seed the cells on the hybrid membrane would require a bit more work and finesse.  We can facilitate the direct seeding of cells onto the hybrid membrane by flipping out system upside down… the flow compartment on the bottom and the shear-free compartment where the cells are at on the top.  Gravity should be able to take care of the rest.