Improved Sensitivity in Low-Input Proteomics using Micro-Pillar Array-based Chromatography

Capitalizing on the massive increase in sample concentrations which are produced by extremely low elution volumes, nano-LC-ESI-MS/MS is currently the most sensitive analytical technology for the comprehensive characterization of complex protein samples. However, despite tremendous technological improvements made in the production and the packing of monodisperse spherical particles for nano-flow HPLC, current state-of-the-art systems still suffer from limits in operation at the maximum potential of the technology. With the recent introduction of the µPAC system, which provides perfectly ordered micro-pillar array based chromatographic support materials, completely new chromatographic concepts for optimization towards the needs of ultra-sensitive proteomics become available. Here we report on a series of benchmarking experiments comparing the performance of a commercially available 50 cm micro-pillar array column to a widely used nano-flow HPLC column for the proteomics analysis of 10 ng tryptic HeLa cell digest. Comparative analysis of LC-MS/MS-data corroborated that micro-pillar array cartridges provide outstanding chromatographic performance and excellent retention time stability, which substantially increase sensitivity in the analysis of low-input proteomics samples, and thus repeatedly yielded almost twice as many unique peptide and unique protein group identifications when compared to conventional nano-flow HPLC columns.