Assessing Iron Deposition in the Brains of 5xFAD Mice by Perls'/DAB Staining

Alzheimer's disease (AD), a common neurodegenerative disease, is the leading cause of dementia in the elderly. Iron deposition is closely linked to the pathogenesis of AD. In the AD brain, elevated iron levels are strongly correlated with characteristic AD pathologies, including β-amyloid plaques, tau neurofibrillary tangles, and apoptosis. Increasing evidence suggests that oxidative stress, due to dysregulated iron metabolism, plays an important role in AD pathophysiology. Understanding the role of iron accumulation in the pathology of AD is, therefore, critical to treating AD. A comprehensive iron staining protocol is essential to detect iron expression and distribution in the brain. This protocol aims to describe a method to assess the quantity and distribution of iron deposition in the brain. We describe the processes involved in reagent preparation, mouse treatment, and preparation of brain sections. In addition, we present a detailed step-by-step protocol for histochemical iron detection in cerebral tissue sections, accompanied by a systematic analytical framework integrating both quantitative assessment and morphological evaluation to ensure a comprehensive interpretation of staining outcomes. This experimental protocol will help researchers understand iron depositions in the brain and support AD research.