High-throughput malaria parasite separation using a viscoelastic fluid for ultrasensitive PCR detection

Abstract

A novel microfluidic device for high-throughput particle separation using a viscoelastic fluid, which enables the rapid detection of extremely rare malaria parasites by using PCR analysis, is proposed. Our device consists of two segments: the 1st stage for sheathless pre-alignment and the 2nd stage for separation based on size-dependent viscoelasticity-induced lateral migration. The use of a high-aspect ratio channel and a viscoelastic polymer solution with low viscosity enables high-throughput processing. The device performance was first optimized using synthetic particles. A mixture of 2 and 10 μm particles was focused at the center plane in the 1st stage. The smaller particles, serving as surrogates for malaria parasites, were subsequently separated in the 2nd stage with a recovery rate of ∼96% at 400 μl min(-1). Finally, separation of the malaria parasites from the white blood cells was performed. At 400 μl min(-1), almost all white blood cells were removed and the malaria parasites were separated with a ∼94% recovery rate and ∼99% purity. Although the initial concentration of the malaria parasites was too low to be detected by PCR analysis, WBC depletion and buffer removal increased the parasite concentration sufficiently such that PCR detection was possible.

Particle manipulations in non-Newtonian microfluidics: A review

“…Recently the authors have further revised their device by replacing the circular microchannel at the 1st stage with a slit-like microchannel and optimizing the dimensions of the rectangular microchannel at the 2nd stage. The new device was demonstrated to separate malaria parasites from a lysed blood in 0.1% HA solution at a flow rate of 400 ml/min with over 90% recovery rate and purity [128]. Sheath-free particle separation in viscoelastic fluid flows has also been implemented in single straight rectangular microchannels.…”

Sheathless Dean-flow-coupled elasto-inertial particle focusing and separation in viscoelastic fluid

“…However, sheath ow is not benecial for channel parallelization design and high-throughput processing. Instead of using sheath ow, Nam et al 36,37 used specic channel geometry to align particles before separation. He used a circular channel followed by a symmetric bifurcation channel and a sudden expansion region to realize the initialization of the particle position and continuous particle separation in elasticity dominant polyvinyl pyrrolidone (PVP) uid.…”

Manipulation of micro‐ and nanoparticles in viscoelastic fluid flows within microfluid systems

“…They studied the effect of blockage ratio, flow rate, and focusing conditions on particle migration within the VEF flow (Romeo, D'Avino, Greco, Netti, & Maffettone, ). These focusing techniques have been specifically employed for biological applications, including targeting of DNAs (Kim et al, ), mammalian cells in anisotropic hydrogels (Lim et al, ), bacteria (Holzner et al, ), blood cells (Nam et al, ; Won Seo et al, ), abnormal erythrocytes (Go, Byeon, & Lee, ), and microalgae (Kim, Youn, & Song, ). The features and performance of different particle focusing techniques in VEFs are summarized in Table .…”

“…The capability and drawback of each method are highlighted. In addition, the present utility of active and passive methods for biological applications and their future potential for biomedical and biological utilization is discussed (Holzner, Stavrakis, & DeMello, ; Kim, Ahn, Lee, & Kim, ; Lim et al, ; Nam et al, ; Won Seo, Ran Ha, & Joon Lee, ).…”