Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by the progressive spread of pathological proteins throughout the brain in a stereotypical manner, following specific neuronal networks. Recent work suggests that pathological proteins may spread via vesicular viral-like trans-synaptic transmission. While this mechanism has been studied in preclinical models, it has never been directly investigated in the human brain. This study aims at developing and optimizing new methods to explore the vesicular viral-like transsynaptic transmission of AD patients using postmortem brain samples from the Geneva Brain Bank (GBB). We successfully implemented a 4x Expansion Microscopy (ExM) protocol on formalin-fixed paraffin-embedded (FFPE) brain sections, achieving uniform tissue expansion while preserving structural integrity, including samples stored since 1998, thus enabling high-resolution imaging of synaptic markers. In parallel, an RNA extraction protocol was optimized for FFPE tissues by extending lysis and final elution incubations times and introducing a chemical cross-link reversal step, which significantly improved RNA yield. Notably, RNA extraction yielded satisfactory results even from samples preserved for over a decade. Importantly, we demonstrated for the first time the feasibility of performing RNA sequencing (RNA-seq) on FFPE brain samples from the GBB. Together, these new tools will actively contribute to advancing the molecular and histological characterization of AD pathology in human tissues, promoting human-based investigations and opening new perspectives for translational research in AD, thereby strengthening future translational studies in the field.