Development of poly-methylmethacrylate micro-gel-electrophoresis chips using excimer laser micromachining

A poly-methylmethacrylate (PMMA) microchip on which the DNA molecules are separated by capillary gel electrophoresis was fabricated. This microchip was able to reduce the DNA sample volume ten times and decrease the separation time to less than one ninth of the traditional slab gel separation. This microchip was fabricated using krypton fluoride (KrF) excimer laser photo-ablation and fusion bonding methods. The excimer laser photo-ablation performs rapid prototyping with great flexibility in changing designs. The PMMA material is much cheaper than other materials, e.g., glass and silicon, used in capillary electrophoresis. This micro-gel-electrophoresis chip successfully separated all of the 11 DNA fragments of the DNA marker ΦX174RF/HaeIII in 5 minutes with a 20V/cm electrical field. The smallest fragment was 72 base pairs in size and the resolution was 10 base pairs. This microchip provides rapid and highly efficient separation of DNA molecules with a small sample volume.