Quantification of Brain-Derived Neurotrophic Factor (BDNF) in In Vitro Systems: Methodologies and Technical Challenges

Brain-Derived Neurotrophic Factor (BDNF) is a critical neurotrophin that regulates neuronal survival, differentiation, synaptic plasticity, and cognitive functions. It plays a vital role in both central and peripheral nervous system development, and its dysregulation has been implicated in several neurological and psychiatric disorders, including Alzheimer’s disease, depression, and Parkinson’s disease. BDNF exists in multiple forms preproBDNF, proBDNF, and mature BDNF each exerting distinct biological effects via receptors such as TrkB and p75^NTR. In vitro models offer a controlled environment to study BDNF’s synthesis, function, and response to pharmacological stimuli. However, accurate quantification of BDNF in these systems remains technically challenging due to its low expression levels, structural complexity, and susceptibility to degradation. This review discusses the biological roles and production of BDNF, highlighting the intracellular processing and regulated secretion pathways. It provides a comprehensive overview of in vitro methodologies commonly employed to detect and measure BDNF including ELISA, Western blotting, immunocytochemistry, qRT-PCR, receptor-binding assays, and reporter gene assays while addressing their relative strengths and limitations. Technical challenges such as isoform specificity, cross-reactivity, and assay sensitivity are critically examined. Advances in detection technologies and model systems are also considered. A deeper understanding of these methodological nuances is essential for accurately interpreting BDNF-related findings and for translating in vitro results into clinically relevant insights.