Abstract
Blood and cerebrospinal fluid (CSF) biomarkers are essential tools for the rapid diagnosis and monitoring of neurodegenerative diseases like Alzheimer's disease (AD). However, even minor variations in sample collection and storage procedures can significantly impact biomarker measurements, emphasizing the importance of standardized operating procedures. This review discusses the main pre-analytical factors that influence biomarker stability, outlines the best practices for blood and CSF collection and storage, and extensively analyzes recent research findings to ensure optimal reproducibility in biomarker studies. It also discusses the future directions and recommendations for enhancing biomarker research methodologies, including advancements in automated processing and quality control measures.