Nuclear yellow is a fluorescent nuclear stain widely used in biological research, particularly as a tracer for studying cell dynamics, neuronal networks, and nuclear structures. It is especially valuable in neuroscience for retrograde labeling of neurons, mapping neural pathways, and visualizing cell nuclei in both live and fixed tissues. The dye's lipophilic nature allows it to permeate intact cell membranes and bind to DNA, enabling live-cell imaging to track nuclear position during cell movement and interactions in real time. It is often used in combination with other fluorescent markers for multicolor labeling, providing detailed insights into cellular processes, tissue organization, and intercellular communication. Its photostability and bright yellow fluorescence under UV excitation make it a reliable tool for advanced microscopy techniques such as confocal and fluorescence microscopy.