Low-cost blood plasma separation method using salt functionalized paper

Abstract

This study describes an extremely low-cost method for separating plasma in a sample of whole human blood on salt functionalized paper by means of osmotic pressure. When a sample of whole blood was introduced onto the salt functionalized paper, plasma dissolves the salt and places the red blood cells (RBCs) in a hypertonic medium. This leads to the generation of osmotic pressure across the cells membrane, and also the crenation of RBCs. The effect of different concentrations of salt on RBC deformation and crenation has been monitored using confocal microscopy. Depending upon the salt concentration, RBCs deform into various shapes under osmotic pressure. At high salt concentration, RBCs turn into deflated thin disks. This increases the RBCs' contact with one another and with fibres in the paper as well. Besides, the counter ion valency charge of the Na + suppresses the thickness of the charged double layer of RBC. Subsequently, aggregation of the deflated RBCs occurs. The aggregates are large enough to be separated chromatographically from the plasma phase of the wicking front.Our results show that 0.5 mL addition of 0.68 M (4% w/v) saline solution (NaCl) can provide sufficient plasma separation on a filter paper for diagnostic applications. A colorimetric blood glucose concentration assay is employed to demonstrate the efficiency of this plasma separation method on paper. The experimental investigation indicates that although the crenation of RBCs forced a small amount of water into plasma, this method is suitable for performing glucose assay in human blood on paper. Our method can enhance bioassays performed on microfluidic paper-based analytical devices (mPADs) by combining the separation and testing of plasma into a single device with no significant additional cost.

Influence of Hydrodynamics and Hematocrit on Ultrasound-Induced Blood Plasmapheresis

“…In particular, the low-Reynolds numbers inherent in most microfluidic systems lead to laminar flows and strong shear rates associated to the parabolic flow profile that can be exploited to drive strong non-Newtonian effects. Over the last decade, unprecedented advances have been reported in developing novel microfabrication techniques and microfluidic devices for blood separation [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Microfabrication techniques have facilitated the proliferation of in vitro studies on blood flows where the use of microfluidic models addressed questions pertaining to the role of microvascular morphology [19,20], blood viscosity [21,22], and hematocrit [23], as well as RBC deformation [24][25][26].…”

Rapid, Self-driven Liquid Mixing on Open-Surface Microfluidic Platforms

“…These devices have attained liquid transport speeds up to 10 mm/s and mixing time scales of about 1 s. The simplest biochemical protocols on surface microfluidic platforms may work well with spot mixing, where the sample is deposited directly on a porous substrate that is pre-suffused with the appropriate analytes or diagnostic chemicals 29 ; but this cannot be extended to more complex protocols that require multiple intermediate steps. Surface microfluidics-based rapid diagnostic strips mostly deploy a separate liquid uptake zone and a testing zone for convenience of sample dispensing and signal readout 30, 31 ; sometimes zone-segregation is adopted to prevent premature sample degradation prior to detection 32 . In specific applications, the sample and the participating reagent in the biochemical protocol mix and react in situ before contacting a third reagent that is used for detection ( e .…”

Emerging trends in paper spray mass spectrometry: Microsampling, storage, direct analysis, and applications

“…A second challenge faced is the extraction of molecules that have a high affinity for RBCs; these molecules will be in much lower quantity in DPS as they will be filtered out with the RBCs. The cost of specialized filter paper for plasma separation can be quite costly compared to the types of filter paper that are used for conventional DBS sampling (Nilghaz & Shen, ; Ryona & Henion, ).…”