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Acoustofluidic rare cell sample preparation

Antfolk, Maria LU (2015)
Abstract
Acoustofluidics utilizes a combination of acoustics, in the form of ultrasound, and microfluidics to manipulate cells

and particles. This has proven to be a versatile method that is gentle to the cells. In this thesis acoustofluidics has been used for

processing rare cells in continuous flow. Rare cells are within this thesis defined as cells that are present in numbers of 1-1000

per mL in a much larger population of background cells. Rare cells present in blood have been of particular interest, and cancer

cells and bacteria have been used as model cells. In this thesis acoustofluidics has first been used to concentrate cells. This was

done by using two-dimensional focusing and a multistage... (More)
Acoustofluidics utilizes a combination of acoustics, in the form of ultrasound, and microfluidics to manipulate cells

and particles. This has proven to be a versatile method that is gentle to the cells. In this thesis acoustofluidics has been used for

processing rare cells in continuous flow. Rare cells are within this thesis defined as cells that are present in numbers of 1-1000

per mL in a much larger population of background cells. Rare cells present in blood have been of particular interest, and cancer

cells and bacteria have been used as model cells. In this thesis acoustofluidics has first been used to concentrate cells. This was

done by using two-dimensional focusing and a multistage acoustofluidic device where sequential concentration steps,

generating moderate concentration factors, could be multiplied into large concentration factors. The usefulness of the method

was then extended as the critical particle focusing size was lowered to also allow focusing of bacteria. This was done through

using two-dimensional focusing, which was shown to change the acoustic streaming pattern to no longer counteract the primary

acoustic radiation force. The new critical particle focusing size was determined to be between 0.5 μm and 0.24 μm in particle

diameter for polystyrene-like particles. In the third paper a simplyfied acoustofluidic device, that does not rely on a clean fluid

sheath flow to prealign the cells or particles before the separation, was presented. To be able to do this the device used only

two-dimensional focusing to prealign the cells. The usefulness of the device was in turn demonstrated with the separation of

cancer cells from white blood cells where it was shown to perform comparably to previously presented devices. In the fourth

paper a separation method was combined with the concentration method presented in the first paper on an integrated device.

The device was shown to be able to simultaneously separate and concentrate cancer cells from white blood cells. Finally, the

previously proposed concentration device was integrated with a DEP single cell trapping device further showing the usefulness

of the acoustofluidic method. Standing alone, the DEP trapping device could only process sample at a flow rate of 4 μL/min

while still maintaining a high trapping efficiency.By integrating the DEP trapping device with the acoustofluidic concentrator

device a higher sample inflow rate could be used as the acoustofluidic device could gear down the flow rate before the sample

entered the DEP trapping device. Together samples could be processed ~10 times faster than using the DEP trapping device

alone, while still recovering over 90% of the cells. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Lee, Abraham, University of California, Irvine
organization
publishing date
type
Thesis
publication status
published
subject
defense location
Lecture hall 1406, building E, Ole Römers väg 3, Lund University, Faculty of Engineering LTH, Lund
defense date
2015-12-11 09:15
ISBN
978-91-7623-527-0
language
English
LU publication?
yes
id
4d093d06-f5a8-4b67-ad1c-3e0cd1db40df (old id 8171879)
date added to LUP
2015-11-18 07:25:20
date last changed
2016-09-19 08:45:16
@phdthesis{4d093d06-f5a8-4b67-ad1c-3e0cd1db40df,
  abstract     = {Acoustofluidics utilizes a combination of acoustics, in the form of ultrasound, and microfluidics to manipulate cells<br/><br>
and particles. This has proven to be a versatile method that is gentle to the cells. In this thesis acoustofluidics has been used for<br/><br>
processing rare cells in continuous flow. Rare cells are within this thesis defined as cells that are present in numbers of 1-1000<br/><br>
per mL in a much larger population of background cells. Rare cells present in blood have been of particular interest, and cancer<br/><br>
cells and bacteria have been used as model cells. In this thesis acoustofluidics has first been used to concentrate cells. This was<br/><br>
done by using two-dimensional focusing and a multistage acoustofluidic device where sequential concentration steps,<br/><br>
generating moderate concentration factors, could be multiplied into large concentration factors. The usefulness of the method<br/><br>
was then extended as the critical particle focusing size was lowered to also allow focusing of bacteria. This was done through<br/><br>
using two-dimensional focusing, which was shown to change the acoustic streaming pattern to no longer counteract the primary<br/><br>
acoustic radiation force. The new critical particle focusing size was determined to be between 0.5 μm and 0.24 μm in particle<br/><br>
diameter for polystyrene-like particles. In the third paper a simplyfied acoustofluidic device, that does not rely on a clean fluid<br/><br>
sheath flow to prealign the cells or particles before the separation, was presented. To be able to do this the device used only<br/><br>
two-dimensional focusing to prealign the cells. The usefulness of the device was in turn demonstrated with the separation of<br/><br>
cancer cells from white blood cells where it was shown to perform comparably to previously presented devices. In the fourth<br/><br>
paper a separation method was combined with the concentration method presented in the first paper on an integrated device.<br/><br>
The device was shown to be able to simultaneously separate and concentrate cancer cells from white blood cells. Finally, the<br/><br>
previously proposed concentration device was integrated with a DEP single cell trapping device further showing the usefulness<br/><br>
of the acoustofluidic method. Standing alone, the DEP trapping device could only process sample at a flow rate of 4 μL/min<br/><br>
while still maintaining a high trapping efficiency.By integrating the DEP trapping device with the acoustofluidic concentrator<br/><br>
device a higher sample inflow rate could be used as the acoustofluidic device could gear down the flow rate before the sample<br/><br>
entered the DEP trapping device. Together samples could be processed ~10 times faster than using the DEP trapping device<br/><br>
alone, while still recovering over 90% of the cells.},
  author       = {Antfolk, Maria},
  isbn         = {978-91-7623-527-0},
  language     = {eng},
  school       = {Lund University},
  title        = {Acoustofluidic rare cell sample preparation},
  year         = {2015},
}