Cells of biomedical interest are, despite their functional
significance,
often present in very small numbers. Therefore the analysis and isolation
of previously inaccessible rare cells, such as peripheral hematopoietic
stem cells, endothelial progenitor cells, or circulating tumor cells,
require efficient, sensitive, and specific procedures that do not
compromise the viability of the cells. The current study builds on
previous work on a rationally designed microfluidic magnetophoretic
cell separation platform capable of throughputs of 240 μL min–1. Proof-of-concept was first conducted using MCF-7
(1–1000 total cells) as the target rare cell spiked into high
concentrations of Raji B-lymphocyte nontarget cells (∼106 total cells). These experiments lead to the establishment
of a magnet-based separation for the isolation of 50 MCF-7 cells directly
from whole blood. Results show an efficiency of collection greater
than 85%, with a purity of over 90%. Next, resident endothelial progenitor
cells and hematopoietic stem cells are directly isolated from whole
human blood in a rapid and efficient fashion (>96%). Both cell
populations
could be simultaneously isolated and, via immunofluorescent staining,
individually identified and enumerated. Overall, the presented device
illustrates a viable separation platform for high purity, efficient,
and rapid collection of rare cell populations directly from whole
blood samples
