Minimize peptide/protein loss due to interactions with custom consumable materials for very low concentration protein samples

Liquid chromatography-mass spectrometry (LC-MS) proteomics is challenged by the detection limit of current mass analyzers for low concentration samples but also especially by material losses during sample preparation steps. The binding of peptides and proteins to the surfaces of consumables significantly reduces the effective concentration in the solution, which further drastically decreases proteomic performance when the concentration of the starting material decreases. In addition to the optimization of the experimental protocols for the preparation of the samples, the nature of the polymeric surface of consumables is crucial. We have therefore designed microvials suitable for low protein concentration sample preparation that can be molded in different polymeric materials. A comparative study has shown that the nature of the polymer material has a strong influence on proteomic performances for low concentration samples ranging from 1.5 to 10ng/µl of proteins (injected quantity less than 10ng). Peptide loss due to surface interaction is not homogeneous with respect to peptide hydrophobicity, hydrophobic peptides being more impacted on commonly used vials. A polar polymer surface should therefore reduce hydrophobic interactions with peptides. Some polymer materials show promising behaviors for low concentration samples, leading to a 20% increase in identification compared to vials commonly used for proteomics.