Multi-laboratory analysis of the variability of shipped samples for proteomics following non-cooled international transport.

Transporting biological samples such as cells or tissues is complicated by the need to maintain integrity and minimise modification and degradation, but this is economically costly as the samples must be shipped in a frozen state. This multi-laboratory study investigated sample variability introduced by non-cooled transport of dried peptide samples for proteomic analysis using mass spectrometry. Human cancer cell tryptic lysates were proteolysed and dried in Australia and shipped by air to Europe and China. Samples were measured using label free mass spectrometry on similar LC-MS systems at all three sites. Preparation and analysis of the specimens in this manner resulted in only minor differences in protein identification and showed high quantitative reproducibility amongst the participating laboratories. We examined any impact on peptide chemical modification and report no discrepancies compared to the starting, non-shipped sample. We conclude that transport of non-cooled, dried peptides has negligible effect on sample integrity for downstream LC-MS analysis and therefore represents a cost-effective option to facilitate international proteomic collaborations. Data is available via ProteomeXchange with identifier PXD008160.