Gravitational Sedimentation Induced Blood Delamination for Continuous Plasma Separation on a Microfluidics Chip

Abstract

Materials and reagents. A Sylgard 184 poly(dimethylsiloxane) (PDMS) kit was purchased from Dow Corning Co. (Midland, MI, USA). Glass plates coated with chromium and photoresist for chip fabrication were obtained from Shaoguang Microelectronics Corp. (Hunan, China). All the other chemicals were of analytical grade and used without further purification. Milli-Q grade water (Millipore Inc., Bedford, MA, USA) was used for preparing all solutions and cleaning microchannels. 10 mM phosphate-buffered saline (PBS, pH 7.4) containing 137 mmol/L NaCl, 2.7 mmol/L KCl, 8.72 mmol/L Na 2 HPO 4 , and 1.41 mmol/L KH 2 PO 4 . Glass capillary (1.0 mm id, 10 cm length) was purchased from Sichuan University Inc. (Chengdu, China). Free hemoglobin test kit was acquired from Jiancheng Bioengineering Institute (Nanjing, China). Silicone tube was from Nuoyawei Inc. (Shenzhen, China). Theophylline was from National Institutes for Food and Drug Control (Beijing, China). Other chemicals were of analytical grade and used without purification.

Size-Based Separation of Particles and Cells Utilizing Viscoelastic Effects in Straight Microchannels

“…[4][5][6] Microfluidic systems have been proven to be promising tools for particle/cell manipulation with higher sensitivity and accuracy than their macroscale counterparts. The last decade has seen extensive development of microfluidic approaches for particle/cell manipulation that resort to immunocapture, 7 externally applied physical fields, [8][9][10][11][12][13][14][15][16][17][18] microfiltration, 19,20 gravitational sedimentation, 21 or deterministic lateral migration. 22,23 More recently, cross-streamline migration induced by the hydrodynamic effects of carrier media, such as inertia 24,25 and viscoelasticity, 26,27 has shown its promise for effective particle/cell manipulation without need of labeling and external force fields.…”

Microfluidic Sample Preparation for Medical Diagnostics

“…Once the sedimentation of cells is complete, the top portion of plasma is drawn into a separate channel. Microfluidic sedimentation for plasma extraction has been successfully demonstrated using various channel configurations (7,(16)(17)(18)(19)(20). Channels of varying depths are commonly used to collect cellular sediments in a lowerbranch channel, which is deeper, and obtain cell-free plasma in upper-branch channels, which are shallower.…”

Phaseguide-assisted blood separation microfluidic device for point-of-care applications

“…But at present, most blood tests are performed using plasma or blood serum, as blood cells may provide a great level of noise, even falsifying the results of a biochemical tests. 2 Therefore, the separation of plasma from whole blood is always the first step for further blood analysis. However, by traditional methods, not only does it require a large volume of the blood sample, but it also takes a long time and the separation process may result in the breaking of the blood cells and in return introducing unnecessary noise in the system.…”

“…However, by traditional methods, not only does it require a large volume of the blood sample, but it also takes a long time and the separation process may result in the breaking of the blood cells and in return introducing unnecessary noise in the system. [1][2][3][4] Meanwhile, the advent of microfluidic devices provides a promising way to overcome these limitations. 5 One approach is to employ active separation forces such as centrifugation, [6][7][8] magnetophoresis, 9 dielectrophoresis (DEP), 10 and acoustic standing waves 11 to selectively separate a) Email: kwangoh@buffalo.edu 1932-1058/2015/9(1)/014106/12/$30.00 V C 2015 AIP Publishing LLC 9, 014106-1 blood cells from plasma.…”