Updated project metadata. Alzheimer’s disease (AD) is the most common form of dementia and one of the leading causes of death in the United States. In past decades, extensive efforts have been devoted to improving our understanding of AD pathogenesis and accelerating biomarker discovery for early diagnosis and clinical treatment of AD. Herein, this study aims to quantify clusterin (CLU) and apolipoprotein E (APOE) in blood samples from AD patients and evaluate these two proteins as potential biomarkers in AD diagnosis. In-house synthesized 5-plex isotopic N,N-dimethyl leucine (iDiLeu) tags were used to label target peptide standards at different concentrations to construct standard curves. Our study reveals that the levels of CLU and APOE exhibit clear disparities in male vs. female AD groups but not in male vs. female non-AD groups, while the levels of serum CLU and APOE do not show statistical differences in the AD groups and non-AD groups. Principal component analysis (PCA) with CLU and APOE showed some separation between the AD and non-AD participants. Significance: Dissecting CLU and APOE heterogeneity in AD pathogenesis may therefore facilitate delineating the pathological relevance for specific pathways between different genders, leading to personalized medicine in the future. Collectively, this study introduces a cost-effective absolute quantitative proteomics strategy for target protein quantitation and lays the foundation for future investigation of CLU and APOE as potential biomarkers for AD.