Immunomagnetic bead-based cell concentration microdevice for dilute pathogen detection.
A cell concentration microdevice for immunomagnetic pathogen isolation from a dilute sample is presented. Cells are driven by integrated on-chip pumps through a fluidized bed of immobilized immunomagnetic beads. Off-chip polymerase chain reaction and capillary electrophoretic analysis are used to determine capture efficiencies of E. coli and to optimize the system. Beads are immobilized after each split in a bifurcated channel system to ensure a balanced distribution of beads in all the capture channels. The addition of a pumping flutter step to repeatedly drive sample through the bead bed was found to enhance capture. Capture efficiencies of 70% and a limit of detection of 2 cfu/microL were achieved; specific capture of E. coli at a concentration of 100 cfu/microL in a 100-fold background of S. aureus is shown. This capture/concentration system is an important step in overcoming the macro-to-micro interface challenge in the development of microdevices for pathogen detection.
Beyor
Nathaniel
N
UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA, 94720, USA.
Seo
Tae Seok
TS
Department of Chemistry, University of California, Berkeley, CA, 94720, USA.|Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Korea.
Liu
Peng
P
UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA, 94720, USA.
Mathies
Richard A
RA
UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA, 94720, USA. rich@zinc.cchem.berkeley.edu.|Department of Chemistry, University of California, Berkeley, CA, 94720, USA. rich@zinc.cchem.berkeley.edu.
D004926:Escherichia coli / Q000166:cytology*; D018189:Immunomagnetic Separation / Q000295:instrumentation / Q000379:methods; D056656:Lab-On-A-Chip Devices; D046208:Microchip Analytical Procedures / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000295:instrumentation / Q000379:methods; D013048:Specimen Handling / Q000295:instrumentation* / Q000379:methods*; D013211:Staphylococcus aureus / Q000166:cytology*