A Critical Evaluation of the PAXgene Tissue Fixation System: Morphology, Immunohistochemistry, Molecular Biology, and Proteomics.

Objectives: To evaluate the PAXgene tissue fixation system.

Methods: Clinical biospecimens (n = 46) were divided into PAXgene-fixed paraffin-embedded (PFPE), formalin-fixed paraffin-embedded (FFPE), and fresh-frozen (FF) blocks. PFPE and FFPE sections were compared for histology (H&E staining) and immunohistochemistry (14 antibodies) using tissue microarrays.

Tube Polypropylene: A Neglected Critical Parameter for Protein Adsorption During Biospecimen Storage.

This biospecimen research case study illustrates the importance of a neglected pre-analytical factor, the polypropylene type of storage tubes. We measured amyloid β1-42 peptide and showed that a non-irradiated, homopolymer type of polypropylene has the lowest adsorption properties.

Viable mononuclear cell stability study for implementation in a proficiency testing program: impact of shipment conditions.

The impact of shipping temperatures and preservation media used during transport of either peripheral blood mononuclear cells (PBMCs) or Jurkat cells was assessed, in view of implementing of a proficiency testing scheme on mononuclear cell viability. Samples were analyzed before and after shipment at different temperatures (ambient temperature, dry ice, and liquid nitrogen) and in different preservation media (serum with cryoprotectant, commercial cryopreservation solution, and room temperature transport medium). Sample quality was assessed by viability assays (Trypan Blue dye exclusion, flow cytometry, Cell Analysis System cell counting (CASY)), and by ELISpot functional assay.

Combined effect of tissue stabilization and protein extraction methods on phosphoprotein analysis.

Preanalytical conditions applied during sample collection and processing can affect the detection or quantification of unstable phosphoprotein biomarkers. We evaluated the consequences of tissue stabilization and protein extraction methods on phosphoprotein analysis. The effects of stabilization techniques (heat stabilization, snap-freezing) and time on the levels of phosphoproteins, including phospho-Akt, p-ERK 1/2, p-IkBα, p-JNK, and p38 MAPK, were evaluated using a BioPlex phosphoprotein assay.

Lithostatine concentration is not useful for assessing the preanalytical variations in biobanked urine samples.

Proteomic research requires high-quality, standardized samples. Quality control (QC) biomarkers, which are sensitive to the collection, processing or storage conditions, would be useful tools to identify compromised samples. This study evaluates the usefulness of renal lithostatine as a QC tool for urine sample processing in daily biobank work.

DNA fingerprinting: a quality control case study for human biospecimen authentication.

This case study illustrates the usefulness of the DNA fingerprinting method in biobank quality control (QC) procedures and emphasizes the need for detailed and accurate record keeping during processing of biological samples. It also underlines the value of independent third-party assessment to identify points at which errors are most likely to have occurred when unexpected results are obtained from biospecimens.

Changes in the intracellular Ca2+ content in human red blood cells in the presence of glycerol.

Changes of the intracellular Ca2+ content in human red blood cells (RBCs) in glycerol-containing solutions and after freeze-thawing the cells with glycerol and subsequent deglycerolization were investigated with the Ca2+-sensitive fluorescent dye fluo-4 using fluorescence microscopy. In the glycerol-containing solutions the Ca2+ content increased when compared with a physiological medium (Hepes buffered saline solution (HBSS)). This effect was most likely a result of an inhibition of the Ca2+ pump.