Reproducibility in urine peptidome profiling using MALDI-TOF.

MALDI-TOF profiling of low molecular weight peptides (peptidome) usage is limited due to the lack of reproducibility from the confounding inferences of sample preparation, data acquisition, and processing. We applied MALDI-TOF analysis to profile urine peptidome with the aims to: (i) compare centrifugal ultrafiltration and dialysis pretreatments, (ii) determine whether using signal LOD (sLOD), together with data normalization, may reduce MALDI-TOF variability. We also investigated the influence of peaks detection on reproducibility.

Usefulness of MALDI-TOF/MS identification of low-MW fragments in sera for the differential diagnosis of pancreatic cancer.

Objectives: To identify new biomarkers of pancreatic cancer (PaCa), we performed MALDI-TOF/MS analysis of sera from 22 controls, 51 PaCa, 37 chronic pancreatitis, 24 type II diabetes mellitus (DM), 29 gastric cancer (GC), and 24 chronic gastritis (CG).

Methods: Sera were purified by Sep-Pak C18 before MALDI-TOF/MS Anchorchip analysis.

Results: Features present in at least 5% of all spectra were selected (n = 160, m/z range, 1200-5000).