Repeated capillary electrophoresis separations conducted on a commercial DNA chip

Multi-sample microchip capillary electrophoresis separations of a DNA sample (i.e. pUC18 DNA Hae III restriction digest) have been conducted on a commercial bioanalyzer. According to the vendor's specifications, a new chip must be used and the gel–dye mix must be used within 2 weeks for the best possible results. However, such a requirement of new chips and fresh reagents is quite costly, especially during preliminary research work, or instructional experiments in teaching labs. Therefore, we have developed a method to clean the microchip, so that the same DNA chip can be inspected and re-used. Our experimental data show that the CE separations conducted on a new chip and on a cleaned chip are comparable without loss in sizing accuracy and reproducibility. The gel–dye mix can also be used many times, longer than 2 weeks as specified by the vendor until the gel–dye changes color. This method will provide cost-saving advantage to laboratories during training and preliminary research work.