(327e) Sacrificial Layer Methods for Making High-Performance Capillary Electrophoresis Microchips

Microfluidic
systems are being utilized increasingly in the analysis of biomolecules,
especially nucleic acids. However, challenges associated with making
high-performance capillary electrophoresis (CE) microchips have hindered the
widespread application of these systems in bioanalysis. Although simple
fabrication is feasible in materials like poly(dimethylsiloxane), the CE
performance in this elastomer is less than ideal; on the other hand, glass CE
microdevices provide high-quality separations, but microchip construction is
more difficult. Hence, we have been developing new and straightforward
strategies for making high-performance CE microdevices, to enhance bioanalysis.
We recently demonstrated a phase-changing sacrificial layer technique that
enables easy solvent bonding of polymer CE microchips.[1] In addition, this
sacrificial layer method works for interfacing ionically conductive membranes
with microchannels, to allow on-chip analyte preconcentration or electric field
gradient focusing.[2] We also reported a thin-film sacrificial layer approach
for fabricating glass CE microdevices, without the need for a thermal bonding
step.[3] We have utilized the CE microchips, made using these simplified
strategies, primarily in the analysis of amino acids, peptides and proteins;
however, these CE microdevices also have excellent potential for application in
the analysis of nucleic acids. Importantly, these advances in CE microchip
fabrication using sacrificial layers should facilitate the rapid
characterization of nucleic acids, proteins and peptides.

References

[1]       Kelly,
R.T.; Pan, T.; Woolley, A.T. Phase-Changing Sacrificial Materials for Solvent
Bonding of High-Performance Polymeric Capillary Electrophoresis Microchips. Anal.
Chem. 77, 3536-3541 (2005).

[2]       Kelly,
R.T.; Li, Y.; Woolley, A.T. Phase-Changing Sacrificial Materials for
Interfacing Microfluidics with Ion-Permeable Membranes to Create On-Chip
Preconcentrators and Electric Field Gradient Focusing Microchips. Anal.
Chem. 78, 2565-2570 (2006).

[3]       Peeni,
B.A.; Conkey, D.B.; Barber, J.P.; Kelly, R.T.; Lee, M.L.; Woolley, A.T.;
Hawkins, A.R. Planar Thin Film Device for Capillary Electrophoresis. Lab.
Chip. 5, 501-505 (2005).