Chip-based nanovials for tryptic digest and capillary electrophoresis Original Research Article

A method for performing tryptic digests in chip-based open vials with volumes of 15 nl has been developed. Working in an enclosed environment with increased humidity counteracted the evaporation of water from the vials during the reaction. Peptide maps of native myoglobin were obtained with capillary electrophoresis and compared with the results of digests performed in conventional 100-μl volumes. The peptide maps, after reactions performed in conventional plastic vials and chip-based vials, showed similar patterns. The reaction showed to be more efficient in the chip-based vials compared to digests performed in conventional plastic vials. The increased efficiency was probably due to the large differences in surface-to-volume ratios and surface dependent reactions. The lowest amount of myoglobin utilized to perform one single digest in a chip-based vial was 12 ng. The corresponding amount of trypsin used was 0.2 ng.