Capillary-composited microfluidic device for heat shock transformation of Escherichia coli

This work describes chemical heat shock transformation of foreign plasmid DNA into bacterial host Escherichia coli cells using a capillary-composited microfluidic device. Transformation processes of the loading, mixing, heat shock and recovery of the transformation mixture were carried out automatically in a linear fashion. In addition, by utilizing the capillary with a hollow cylindrical chamber as heating source, simple, low cost local heat shock with accurate heat shock time to transformation mixture was obtained on the microdevice. Results demonstrated that plasmid DNA could be effectively transformed into E. coli, and the transformation efficiency and frequency were as the same level or better than conventional tube-based method. This work complements other microfluidic technologies for potential gene cloning and functional genomics studies.