DNA separation by microchip electrophoresis using low-viscosity hydroxypropylmethylcellulose-50 solutions enhanced by...

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Low-viscosity polymer solutions are crucial for DNA separations in microfluidic devices.
• Hydroxypropylmethylcellulose-50 (HPMC-50) is a potential candidate for such applications.

Purpose of the Study:

• To investigate dilute, low-viscosity HPMC-50 solutions with polyhydroxy additives as effective DNA separation media.
• To optimize operational variables for enhanced DNA fragment separation in microchips.

Main Methods:

• Utilized polymethylmethacrylate (PMMA) microchips with a 30 mm channel.
• Tested 2% HPMC-50 solutions with varying concentrations of mannitol, glucose, or glycerol as additives.
• Investigated electric field strength, intercalator concentration, polymer concentration, and additive concentration.

Main Results:

• Achieved fast (within 170 s) separation of DNA fragments (72-1353 bp) using 2% HPMC-50 with 8% mannitol, 8% glucose, or 10% glycerol.
• Demonstrated superior performance compared to highly concentrated HPMC-50 solutions.
• Observed improved separation with Tris-EDTA buffer, suggesting boric acid is not essential.

Conclusions:

• Dilute HPMC-50 solutions with polyhydroxy additives offer efficient DNA separation in microfluidic systems.
• Polyhydroxy additives enhance matrix-DNA interactions through hydrogen bonding, improving electrophoretic separation.
• This formulation provides microchannel coating and DNA separation in a single step, simplifying micro-total analysis systems.