Microfluidic devices with bubble cells have been fabricated on poly(methyl methacrylate) (PMMA) plates and have been employed for the analysis of DNA using polyethylene oxide (PEO) solutions. First, the separation channel was fabricated using a wire-imprinting method. Then, wires with greater sizes or a razor blade glued in a polycarbonate plate was used to fabricate bubble cells, with sizes of 190-650 μm. The improvements in resolution and sensitivity have been achieved for large DNA (> 603 base pair, bp) using such devices, which depend on the geometry of the bubble cell. The main contributor for optimal resolution is mainly due to DNA migration at lower electric field strengths inside the bubble cell. On the other hand, slight losses of resolution for small DNA fragments have been found mainly due to diffusion, supported by the loss of resolution when separating two small solutes. With a bubble cell of 75 μm (width) × 500 μm (depth), the sensitivity improvement up to 17-fold has been achieved for the 271 bp fragment in the separation of ΦX-174/Haelll DNA restriction fragments. We have also found that a microfluidic device with a bubble cell of 360 μm x 360 μm is appropriate for DNA analysis. Such a device has been used for separating DNA ranging from 8 to 2176 bp and polymerase chain reaction (PCR) products amplified after 30 cycles, with rapidity and improvements in the sensitivity as well as resolution.
|Number of pages||8|
|Publication status||Published - 2002 Aug 1|
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Clinical Biochemistry