US Patent 7214427 - Quantum dot tag subject to microfluidic control

http://www.freepatentsonline.com/7214427.html

Electrophoretic pumping is a method using electric fields to move minute quantities of fluid applicable to biological and chemical analysis. This patent from Aviva Biosciences teaches the formation of beads to facilitate such pumping and which can also be used as quantum dot tags for tracking particular biofluids. Claim 22 reads:

22. A bead, which bead comprises: a) a magnetizable substance; and b) an electrically conductive substance, and a quantum dot.