DiI Labelling with a Paintbrush: a Low-cost Alternative to DiOlistic Labelling in Neurons v1

DiOlistic labelling is a high-throughput technique commonly used to label neurons in fixed brain tissue using the fluorescent lipophilic carbocyanine dye, DiI. It labels a large population of neurons in a dense yet distributed pattern, making it ideal for morphological studies. However, DiOlistic labelling typically requires an expensive commercial gene gun. Therefore, our protocol presents a low-cost alternative using materials that are already available in most laboratories (e.g. a plastic 12-well culture plate lid) or easily acquired at a low price (e.g. a paintbrush). We detail the DiI labelling process, including the preparation, delivery, incubation, and post-processing steps. Overall, this protocol labels a large population of neurons in a dense yet distributed pattern and, therefore, is a simple and low-cost alternative to DiOlistic labelling.