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Title: Soft inertial microfluidics for high throughput separation of bacteria from human blood cells

Abstract

We developed a new approach to separate bacteria from human blood cells based on soft inertial force induced migration with flow defined curved and focused sample flow inside a microfluidic device. This approach relies on a combination of an asymmetrical sheath flow and proper channel geometry to generate a soft inertial force on the sample fluid in the curved and focused sample flow segment to deflect larger particles away while the smaller ones are kept on or near the original flow streamline. The curved and focused sample flow and inertial effect were visualized and verified using a fluorescent dye primed in the device. First the particle behavior was studied in detail using 9.9 and 1.0 {micro}m particles with a polymer-based prototype. The prototype device is compact with an active size of 3 mm{sup 2}. The soft inertial effect and deflection distance were proportional to the fluid Reynolds number (Re) and particle Reynolds number (Re{sub p}), respectively. We successfully demonstrated separation of bacteria (Escherichia coli) from human red blood cells at high cell concentrations (above 10{sup 8}/mL), using a sample flow rate of up to 18 {micro}L/min. This resulted in at least a 300-fold enrichment of bacteria at a wide rangemore » of flow rates with a controlled flow spreading. The separated cells were proven to be viable. Proteins from fractions before and after cell separation were analyzed by gel electrophoresis and staining to verify the removal of red blood cell proteins from the bacterial cell fraction. This novel microfluidic process is robust, reproducible, simple to perform, and has a high throughput compared to other cell sorting systems. Microfluidic systems based on these principles could easily be manufactured for clinical laboratory and biomedical applications.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Earth Sciences Division
OSTI Identifier:
949965
Report Number(s):
LBNL-1539E
TRN: US200908%%109
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Lab on a Chip
Additional Journal Information:
Journal Name: Lab on a Chip
Country of Publication:
United States
Language:
English
Subject:
54; 58; BACTERIA; BLOOD CELLS; DYES; ELECTROPHORESIS; FLOW RATE; GEOMETRY; PROTEINS; REMOVAL; REYNOLDS NUMBER; SORTING

Citation Formats

Wu, Zhigang, Willing, Ben, Bjerketorp, Joakim, Jansson, Janet K, and Hjort, Klas. Soft inertial microfluidics for high throughput separation of bacteria from human blood cells. United States: N. p., 2009. Web. doi:10.1039/b817611f.
Wu, Zhigang, Willing, Ben, Bjerketorp, Joakim, Jansson, Janet K, & Hjort, Klas. Soft inertial microfluidics for high throughput separation of bacteria from human blood cells. United States. https://doi.org/10.1039/b817611f
Wu, Zhigang, Willing, Ben, Bjerketorp, Joakim, Jansson, Janet K, and Hjort, Klas. 2009. "Soft inertial microfluidics for high throughput separation of bacteria from human blood cells". United States. https://doi.org/10.1039/b817611f. https://www.osti.gov/servlets/purl/949965.
@article{osti_949965,
title = {Soft inertial microfluidics for high throughput separation of bacteria from human blood cells},
author = {Wu, Zhigang and Willing, Ben and Bjerketorp, Joakim and Jansson, Janet K and Hjort, Klas},
abstractNote = {We developed a new approach to separate bacteria from human blood cells based on soft inertial force induced migration with flow defined curved and focused sample flow inside a microfluidic device. This approach relies on a combination of an asymmetrical sheath flow and proper channel geometry to generate a soft inertial force on the sample fluid in the curved and focused sample flow segment to deflect larger particles away while the smaller ones are kept on or near the original flow streamline. The curved and focused sample flow and inertial effect were visualized and verified using a fluorescent dye primed in the device. First the particle behavior was studied in detail using 9.9 and 1.0 {micro}m particles with a polymer-based prototype. The prototype device is compact with an active size of 3 mm{sup 2}. The soft inertial effect and deflection distance were proportional to the fluid Reynolds number (Re) and particle Reynolds number (Re{sub p}), respectively. We successfully demonstrated separation of bacteria (Escherichia coli) from human red blood cells at high cell concentrations (above 10{sup 8}/mL), using a sample flow rate of up to 18 {micro}L/min. This resulted in at least a 300-fold enrichment of bacteria at a wide range of flow rates with a controlled flow spreading. The separated cells were proven to be viable. Proteins from fractions before and after cell separation were analyzed by gel electrophoresis and staining to verify the removal of red blood cell proteins from the bacterial cell fraction. This novel microfluidic process is robust, reproducible, simple to perform, and has a high throughput compared to other cell sorting systems. Microfluidic systems based on these principles could easily be manufactured for clinical laboratory and biomedical applications.},
doi = {10.1039/b817611f},
url = {https://www.osti.gov/biblio/949965}, journal = {Lab on a Chip},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 05 00:00:00 EST 2009},
month = {Mon Jan 05 00:00:00 EST 2009}
}