Evaluation of DNA Fragment Sizing and Quantification by the Agilent 2100 Bioanalyzer (Technical Briefs‪)‬

Capillary electrophoresis (CE) achieves efficient separation of molecular species by the application of high voltages to samples in solution (1). Commercial CE units, available for slightly more than a decade, have found numerous applications (2-6), but are expensive (;$60 000) and require substantial user training and experience. Recent advances have allowed CE to be performed on microchip devices (7-11 ). We evaluated the Agilent 2100 Bioanalyzer (Agilent Technologies), which represents a new generation of CE instruments that use this technology. The Bioanalyzer is relatively inexpensive (~$18 000) and is simple to operate, requiring only routine pipetting and basic computer skills. Typically, 12 nucleic acid samples can be sized and quantified on a disposable chip within 30 min. Chips are fabricated from glass and comprise an interconnected network of fluid reservoirs and microchannels, which must be filled with a gel-dye mixture. Each chip contains 16 wells: 3 for loading the gel-dye mixture, 1 for a molecular size ladder, and 12 for experimental samples. The movement of nucleic acids through the microchannels is controlled by a series of electrodes, each of which is independently connected to a common power supply. The Bioanalyzer displays data as both migration-time plots and as computer-generated virtual gels. Traditional CE operating variables [temperature, voltage, capillary material, and pH, ionic strength, and viscosity of buffer (12)] cannot be modified. The instruments costs ~$18 000, and chips cost ~$12-18 per chip ($1-1.50 per sample).