Pre-analytical operating procedures for serum Low Molecular Weight protein profiling.

Department of Laboratory Medicine and Advanced Biotechnologies, IRCCS San Raffaele Pisana, Rome, Italy.
Journal of proteomics (Impact Factor: 3.93). 09/2009; 73(3):667-77. DOI: 10.1016/j.jprot.2009.09.006
Source: PubMed

ABSTRACT Biological specimen collection and storage are an integral component of serum proteomics research. Although many efforts have been posed to address the effects of pre-analytical procedures, standardized protocols for collection and storage of samples for Low Molecular Weight (LMW) proteome profiling are still needed. Here we report a systematic analysis on the influence of pre-analytical factors [clotting times, temperature and time storage, addition of protease inhibitor (PI)] on serum LMW proteome profiling. Moreover, a comparison between manual versus automated peptide purification by functionalized magnetic bead-based MALDI-MS approach was performed. The results demonstrated best serum LMW proteins recovery and stability using a clotting time between 1 and 2h, with serum stored up to 2h either at room temperature or at 4 degrees C, independently of PI addition. PI addition to whole blood resulted in a lower number of LMW peaks detected. Finally, minimal effects on serum proteome profiles were observed after 1-month storage at -80 degrees C, independently of PI addition on whole blood and/or serum. In conclusion, the use of standardized pre-analytical and storage procedures together with an automated peptide purification might minimize potential bias on serum LMW profiling results, thus allowing a better homogeneity and reproducibility in future proteomics studies.

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