Used in neuroscience research for intracellular labeling of neurons during electrophysiological recordings. Allows visualization of cell morphology after patch-clamp experiments. Commonly used in fixed tissue for immunohistochemical detection with avidin-biotin-peroxidase or fluorescent streptavidin conjugates. Enables detailed mapping of neuronal circuits and connectivity in brain slices. Also utilized in biotin tagging for protein purification and detection in molecular biology applications.