Cyto-analysis of rare cells often requires separation and detection with each procedure posing substantial challenges. This paper presents a disk-based microfluidic platform for both procedures via an immunomagnetic negative selection process. The microfluidic platform's unique features include a multistage magnetic gradient to trap labeled cells in double trapping areas, drainage of fluid to substantially shorten detection time, and a bin-like regions to capture target cells to facilitate a seamless enumeration process. Proof-of-concept was conducted using MCF7 as target rare cells (stained with anti-cytokeratin-FITC antibodies) spiked into Jurkat Clone E6-1 non-target cells (labeled with anti-CD45-PE and anti-PE BD magnetic beads). Then, mononuclear cells (MNC) from healthy blood donors were mixed with MCF7s, modeling rare cells, and tested in the disk. Results show a non-linear magnetic coupling effect of the multistage magnet substantially increased the trapping efficacy over that of a single magnet, contributing to the depletion rate of Jurkats, which reaches 99.96%. Detection time is extensively shortened by depletion of 95% of non-cell-containing fluid in the collection area. The average yield of detected MCF7 cells is near-constant 60 ± 10% over a wide range of rarity from 10(-3) to 10(-6) and this yield also holds for the MCF7/MNC complex mixture. Comparison with autoMACS and BD IMagnet separators revealed the average yield from the disk (60%) is superior to that of autoMACS (37.3%) and BD IMagnet (48.3%). The advantages of near-constant yield, roughly 30 min of operation, an acceptable level of cell loss, and potentially low cost system should aid in cyto-analysis of rare cells.
BACKGROUND:Circulating endothelial cells (CECs) in the blood are rare but have been shown to be associated with various diseases. With the ratio of CECs to peripheral blood mononuclear cells (PBMCs) less than 1 part per thousand, their separation from PBMCs and detection are challenging. We present a means of detecting CECs from PBMCs via an economical microfluidic disk with a model cell system [human umbilical vein endothelial cells (HUVECs) in PBMCs], along with demonstration of its efficacy clinically.
Cyto-analysis of rare cells often requires separation and detection with either procedure possesses substantial challenge. This paper presents a disk-based microfluidic platform for both procedures via immunomagnetic negative selection process. Proof-of-concept was conducted using wide range of MCF7 as target rare cells and spiked into Jurkat as nontarget cells. Then, mononuclear cells (MNC) from healthy blood donors were mixed with MCF7s, modeling rare cells, and tested in the disk. Results show the average yield of detected MCF7 is near-constant 60±10% over a wide range of rarity from 10 -3 to 10 -6 and this yield also holds for MCF7/MNC complex mixture. Comparison with autoMACS and BD IMagnet separators revealed the average yield from the disk (60%) is superior to that of autoMACS (37.3%) and BD IMagnet (48.3%).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.