Optimization of a targeted metabolomics kit for dried blood spots analysis and longitudinal comparison with serum

Targeted metabolomics kit-based assays are widely used for quantitative metabolic profiling in clinical research. However, they are primarily validated for conventional matrices such as plasma and serum. Their direct application to dried blood spots (DBS) cannot be assumed and requires specific optimization due to intrinsic matrix-specific differences. This study aims to optimize the TMIC MTX MEGA assay for DBS analysis and matrix comparison. Validation was then conducted using paired longitudinal DBS and serum samples from participants in a clinical study. Principal component analysis revealed matrix-driven separation, highlighting clear distinctions of plasma/serum from DBS and confirming intrinsic matrix differences. Despite global differences, longitudinal trends across metabolite classes and at individual metabolite levels were largely concordant between DBS and serum. Class-specific differences were observed, particularly among lipid species and metabolites influenced by intracellular contributions, consistent with known biological factors. Although absolute concentrations differed for several metabolites, relative temporal changes were preserved. These findings demonstrate that targeted metabolomics kit-based assays can be successfully applied to DBS after specific workflow optimization. Overall, DBS provides reliable longitudinal metabolic profiling, supporting its use as an alternative matrix for minimally invasive sampling in clinical and population-based studies and targeted metabolomics applications.基于靶向代谢组学试剂盒的检测分析方法，现已广泛应用于临床研究的定量代谢谱分析工作。然而，此类检测方法的验证多针对血浆、血清等常规样本基质，若直接应用于干血斑（Dried Blood Spots, DBS）则缺乏合理性，且因不同基质存在固有差异，需开展针对性优化。本研究旨在针对干血斑分析与基质对比场景，优化TMIC MTX MEGA检测试剂盒。随后，本研究借助某临床研究中受试者的配对纵向干血斑与血清样本完成验证工作。主成分分析（Principal Component Analysis）结果显示，样本基质因素驱动样本聚类分离，清晰呈现出血浆/血清与干血斑之间的显著差异，证实了不同基质的固有区别。尽管整体代谢谱存在差异，但干血斑与血清在代谢物类别及单个代谢物层面的纵向变化趋势总体一致。研究同时观察到类别特异性差异，尤其在脂质种类及受细胞内代谢调控的代谢物中较为显著，这与已知生物学因素相吻合。尽管部分代谢物的绝对浓度存在差异，但其相对时间变化趋势得以保留。上述研究结果证实，经针对性实验流程优化后，基于靶向代谢组学试剂盒的检测方法可成功应用于干血斑样本分析。总体而言，干血斑可实现可靠的纵向代谢谱分析，支持其作为微创采样的替代基质，应用于临床研究、人群研究及靶向代谢组学相关场景。