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Blood Separation in Microfluidic Devices
Group #5
Eric Chung
Scott Darby
Casey Reynolds
Jeff Turner
Background
• Microfluidic Devices:
▫ Uses:
 Point-of-care diagnosis
 Low-Cost for mass
production
 Laminar Flow
• White Blood Cells:
▫ Comprise most of the
adaptive immune response
▫ Intercellular Pathways must
be completed for activation
Type
Function
%in
Humans
Neutrophil
Defense
against
infection
65%
Eosinophil
Parasitic
Infection
4%
Basophil
Allergic
responses
1%
Lymphocyte
Immune
System
25%
Monocyte
Vacuum
Cleaner
~3%
Macrophage
Phagocytosing ~3%
macrophage
Valve Bank
(With Fluorescent
Dyes A, B, and C)
Whole
Blood
Confocal
Microscope
Reverse
Aspiration
Pump
Direction of Experiment
Valve Pressure
Releases Specific
Dye Marker (C)
Close-up
of Device
• Red Blood cells,
unaffected by dye,
and free to flow
through filters.
PDMS
Traps
• B-Cells, marked with
dye marker C and
contained within traps.
• Other types of
Leukocytes,
unaffected by dye.
Direction
of Flow
Current Technologies
• Flow Cytometry (FACS)
▫ High cost
▫ Requires relatively large fluid
samples
▫ Size limitations
▫ Only analyzes large numbers
of cells
▫ No time scale
Design Objectives
• To create:
▫ A microfluidic blood cell sorter used for taking multiple
measurements of single B-cells over time
 Physical Size
 CD markers
▫ A novel pump system using reverse aspiration
▫ A valve bank that allows for regulated inputs in real-time
 Reduces opportunity for air bubble formation
Device Uses
• Trapping and targeting of white blood cells,
focusing on B-cells
• Identifying disease specific pathways
▫ Can find specific action of pathogen to enhance
targeting of drugs
• Regulation of a variety of inputs with a single
input source
Valve Bank
Microfabrication – Blood Sorter
• Device constructed from PDMS
plasma bonded to glass cover sheet
Valve Bank
(With Fluorescent
Dyes A, B, and C)
Whole
Blood
Confocal
Microscope
Reverse
Aspiration
Pump
Direction of Experiment
Valve Pressure
Releases Specific
Dye Marker (C)
Close-up
of Device
• Red Blood cells,
unaffected by dye,
and free to flow
through filters.
PDMS
Traps
• B-Cells, marked with
dye marker C and
contained within traps.
• Other types of
Leukocytes,
unaffected by dye.
Direction
of Flow
Questions
• What is the most efficient flow rate for cell trapping?
• What cell markers elicit the best response from B-cells?
• Does reverse aspiration provide adequate pressure to
flow whole blood?
• Can a valve bank be utilized without introducing air into
such a sensitive system?
• Will this process be detrimental to cell integrity to a
point where test results are unreliable?
Progress
• Completed:
▫ To create a flow system powered by reverse aspiration
▫ Receive approval for human blood experimentation
▫ To successfully separate white blood cells from whole blood
• In Progress:
▫ To create a valve bank capable of switching chemical
reagents while maintaining continuous flow
• Long Term:
▫ To simulate intermediary cell cycle steps with our trapped
cells