According to PharmaFluidics, more sample components can be identified if separation channels are etched in silicon.
The practice of bottom-up proteomics relies to a large extent on the separation performance that can be achieved with state-of-the-art nano LC-MS/MS equipment. Depending on the sample complexity or the instrument time that can be dedicated to a certain sample, different LC columns and corresponding LC-MS/MS methods are often required. When comprehensive proteome analysis with deep coverage is needed, relatively long columns (lengths up to 75 cm) are typically operated with long and shallow solvent gradients, delivering the highest chromatographic performance. This is indeed a good strategy if very complex samples need to be analyzed and when as much information as possible needs to be retrieved from these samples. However, routine daily proteome analysis often deals with simpler samples or demands increased sample throughput, making total analysis times above 120 min undesirable or even impossible. As an alternative to the conventional packed-bed nano LC column, PharmaFluidics offers a micromachined nano LC chip column called the micro Pillar Array Column (μPAC™). The inherent high permeability and low on-column dispersion obtained by the perfect order of the separation bed is what sets μPAC™-based chromatography apart from conventional chromatography. The peak dispersion originating from heterogeneous flow paths in the separation bed is eliminated (no A-term contributions), and therefore, components remain much more concentrated during separation. The free-standing nature of the pillars also leads to much lower backpressure, allowing the use of very long columns with exceptional peak capacities. To complement its innovative 200 cm long column, which is designed to perform comprehensive and sometimes time-consuming proteome research, PharmaFluidics has introduced a 50 cm long μPAC™ column. It can be used in more routine research. With an internal volume of 3 μL, this column is suited to perform high-throughput analyses with shorter gradient solvent times (30-, 60-, and 90-minute gradients), and it can be used over a wide range of flow rates, between 100 and 2000 nL/min.