Table 2.

List of important factors to consider in AD blood biomarker research

Pre-analytical	Analytical	Post-analytical
• Participant preparation: fasting status, blood draw time • Plasma vs. serum • Blood draw devices • Blood collection tubes • Blood draw order • Blood tube filling height • Blood tube inversion • Serum clotting time • Time from blood draw to centrifugation • Centrifugation parameters, including speed, time, and temperature • Time from centrifugation to storage • Storage temperature • Microtubes for specimen storage • Freeze/thaw cycles • Transportation temperature • Proper tube labeling to minimize error	• Sample thawing and homogenization • Centrifugation for particulate removal • Prompt storage of unused specimen • Inclusion of calibrators • Inclusion of QC samples • Sample measurement order • Sample blinding • Assay orders for multi-assay studies • Inclusion of bridging samples • Order for longitudinal samples • Batches/lots for reagent and consumable • Selection of analytical platforms	• Evaluation of calibrator curves • Evaluation of QC results • Adjustment of potential moderating variables • Full description of methods • Disclosure of assay performance