To the Editor: Serum has proven a difficult matrix for mass spectrometry (MS)-based clinical proteomic profiling. Problems occur mainly as a result of preanalytical variables in sample handling and processing, causing substantial changes in MS peptide profiles (1 ) that can completely abolish meaningful data interpretation (2 ). The necessary rigorous standardization of sample collection and pr...

The use of plasma lactate to assess metabolic or circulatory impairment requires definition of critical preanalytical and analytical parameters. Stability has been documented for only 15 min after acquisition when samples were collected with fluoride and transported on ice. We examined time elapsed before analysis, storage temperature, and the antiglycolytic agent used to define preanalytical c...

Total turnaround time (TAT) in laboratory testing has been traditionally characterized as the time from specimen collection to the reporting of results (1, 2). Despite improvements in analytical testing systems (i.e., automation), little to no measurable improvements have been demonstrated for the preanalytical phase of TAT. Efforts to address some aspects of the preanalytical phase, specifical...

BACKGROUND Preanalytical standardization is required for a reliable quantification of the signaling molecules sphingosine-1-phosphate (S1P), sphinganine-1-phosphate (SA1P) and sphingosine (SPH). METHODS Methanolic protein precipitation of 15μL EDTA-plasma was applied prior to analysis. Sphingolipids were separated in 3min by hydrophilic interaction liquid chromatography (HILIC, SeQuant™ ZIC®-...

BACKGROUND There is great interest in circulating microRNAs (miRNAs) as disease biomarkers. Translating promising miRNAs into validated clinical tests requires the characterization of many preanalytical and analytical parameters. METHODS miRNAs were extracted from serum and plasma samples of healthy volunteers, and miRNAs known to be present in serum and plasma (miR-15b, miR-16, miR-24, and m...