A modified and highly sensitive Golgi–Cox method to enable complete and stable impregnation of embryonic neurons

The FD Rapid GolgiStain Kit (FD NeuroTechnologies, Inc., Ellicott City, MD) was developed using an improved Golgi–Cox impregnation method to provide stable, sensitive, and convenient staining of mature neurons. However, embryonic neurons cannot be clearly visualized using this method. We have further improved the Golgi–Cox method by introducing an additional aldehyde fixation step before impregnation; thus, we can stably and sufficiently impregnate fetal brain neurons so that even the fine branches of the dendritic trees are visible.