Dynamic acoustic field activated cell separation (DAFACS).

G. D. Skotis,A. L. Bernassau,D. R. S. Cumming,J. N. Roberts,M. O. Riehle

doi:10.1039/c4lc01153h

Abstract

Advances in diagnostics, cell and stem cell technologies drive the development of application-specific tools for cell and particle separation. Acoustic micro-particle separation offers a promising avenue for high-throughput, label-free, high recovery, cell and particle separation and isolation in regenerative medicine. Here, we demonstrate a novel approach utilizing a dynamic acoustic field that is capable of separating an arbitrary size range of cells. We first demonstrate the method for the separation of particles with different diameters between 6 and 45 μm and secondly particles of different densities in a heterogeneous medium. The dynamic acoustic field is then used to separate dorsal root ganglion cells. The shearless, label-free and low damage characteristics make this method of manipulation particularly suited for biological applications. Advantages of using a dynamic acoustic field for the separation of cells include its inherent safety and biocompatibility, the possibility to operate over large distances (centimetres), high purity (ratio of particle population, up to 100%), and high efficiency (ratio of separated particles over total number of particles to separate, up to 100%).

Highlights

Advances in diagnostics, cell and stem cell technologies drive the development of application-specific tools for cell and particle separation
Once dynamic acoustic field (DAF) had been successfully used to discriminate within heterogeneous mixture particles by their sizes and densities in multiple cycles, we progressed to show the capacity of DAF to isolate dorsal root ganglion cells from a mixture of cells and debris as it develops during tissue digestion
A detailed evaluation has been carried out using polystyrene and iron-oxide filled particles, prior to applying the technique to the separation and purification of recovered dorsal root ganglion cells from the myelin cells

Summary

Introduction

Cell and stem cell technologies drive the development of application-specific tools for cell and particle separation. Achieving cell separation[21] utilizing ultrasonic manipulation by frequency sweeping[11,22] has been previously demonstrated; this method has several critical disadvantages. Unstable forces are generated which leads to differences in the movement of individual trapped particles of the same size or property.[23,24] Secondly, this method exclusively allows small particle displacement, which in turn limits sorting efficiency. An alternative to manipulating acoustic frequency is to control the signal phase; it has been demonstrated that shifting the phase of acoustic travelling waves can be used to control the position of micro-particles suspended in an aqueous medium.[25] When two opposing transducers are excited, a linear interference pattern of nodes and antinodes is formed in the interstitial media. The shift of the node position translates to a change in the position of the trapped micro-particles.[27,28]

Methods

Results

Conclusion