Nanofluidic Microsystems for Advanced Biosample Preparation

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Nanofluidic Microsystems for Advanced Biosample
Preparation
Microfluidics Tech Fair 2006

• Ying-Chih Wang (ycwang_at_mit.edu)1, Jianping Fu,
  Yong-Ak Song and Jongyoon Han 2,3
• 1Department of Mechanical Engineering,
  2Biological Engineering Division, 3Department of
  Electrical Engineering and Computer Science,
• Massachusetts Institute of Technology, Cambridge,
  MA 02139
• October 3rd, 2006

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The need and the market for sample preparation

• Market of Proteomics, 1.3 billion and growing
  (13 annually)
• Greatest challenge in proteomics
• Sample complexity (gt20,000 different proteins) ?
  Purification required
• 2D gel electrophoresis, 800 M in 2004 (1.8B
  2011)
• Time and labor consuming
• Poor recovery for low abundance sample after
  multiple steps
• Consumers Biologist, Pharmaceutical RD,
  clinical diagnostics

IN
Detection
Separation
Fraction
(Mass Spectrometry)
(2D gel analysis)
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Our Approach (gel free)
Complex peptide/protein mixture
Sample preparation in microfluidic chip
Size-based separation
Charge-based separation
Preconcentration
Sensing/Detection
Droplet/Electrospray
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Our Core (Patented) Techniques

• Nanofluidic molecular sieving
• Continuous biomolecule size separation
• Microfluidic charge-based sorting
• Continuous biomolecule charge separation
• Electrokinetic nanofluidic preconcentrator
• Rapid molecular trapping

Enable rapid and economical low-abundant sample
identification
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Fabrication Method of Nanofluidic Devices
Fabrication DO NOT need nanolithography Thin
channel instead of Narrow channel Uniform, flat
nanofluidic channel confirmed down to 20nm
Making nanofluidic (20 nm) device using standard
microfabrication techniques!
Pan Mao and Jongyoon Han, 2005, EECS / BE / MIT
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Core Technology INanofluidic filter array for
size-based separation
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Molecular Separation in 2-D Nanofilter Arrays

• Physically hinders
• protein migration
• Continuous two-
• dimensional separation

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Continuous flow separation video (All 20? Speed)
Ogston sieving, DNA (50 bp 766 bp, 5 bands)
Ogston sieving, protein complex (11 kDa vs. 116
kDa)
Entropic trapping, DNA (2 kbp 23 kbp, 6 bands)
1960 µm
1960 µm
4080 µm
Small Large
Large Small
Size
Large Small

• PCR marker.
• Ex70 V/cm, Ey100 V/cm

• ? DNA - Hind III digest.
• Ex380 V/cm, Ey400 V/cm

• SDS-Protein complex.
• Ex150 V/cm, Ey200 V/cm.

• A general but unique size-based separation tool.
  Even larger DNA (Mbp) possible with this method.

J. Fu, A. Stevens, S. R. Tannenbaum J. Han.
subminted
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Core Technology IICharge separation driven by
diffusion potential (no external power)
c200mM
c1mM

• Different diffusivities of the buffer ions
• generate a diffusion potential across the
• liquid junction
• Potential gradient (electric field) utilized
• for binary sorting

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Ampholyte-free pI-based separation
Continuous-flow operation
Song, Y.-A., Hsu, S., Stevens, A.and Han, J.
Anal. Chem. (2006).
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Core Technology III Preconcentration by Ion
Selective Nanofluidic Channels
Electrical double layer overlapping
Device layout
Wang et al, Anal. Chem., 77, 4293
micro channel cross section 1x10mm
50mmx50mm length 1 -2 cm nano channel cross
section 40nm x20mm 40mmx200mm length 100 -200mm
Allen, Bard Electrochemical Methods
Fabrication Mao et al.,  Lab Chip, 2005, (8),837-
844
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Preconcentration Mechanism
ET ( )
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Million-fold Protein Concentration Enhancement
107
105
Regular, stable pore size contributes its long
term stability
Wang, Y.-C., Stevens, A. L.and Han, J. Anal.
Chem. 77, 4293-4299 (2005).
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Vision The Integrated sample preparation device
Protein Concentrator
Silicon-based technologies make integration easier
Charge Separation
Size separation
Pre-concentration
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Developing Timeline

• Our advantages
• Rapid biomolecule separation (lt30 mins)
• Minimum sample consumption (lt1 ml)
• Automated solution for biomarker discovery/
  tracking
• Better recovery compares to 2D gel (no post
  processing)
• Direct coupling to mass spectroscopy or
  immunoassay

Principal Investigator Jongyoon (Jay) Han,
jyhan_at_mit.edu