A rapid, easy technique for defining detailed anatomical orientation in pre-deparaffinized tissue sections

During our previous histochemical studies on changes in anterograde and retrograde degeneration following optic nerve transection in rats, it was necessary to make brain sections in which various bilateral components of the visual system were symmetrically included. We discovered a rapid, easy technique that defines a detailed anatomical orientation in pre-deparaffinized tissue sections. The procedure is as follows: several drops of 1% toluidine blue solution are injected with a syringe under the paraffin section on the glass slide after the sections are cut and floated on warm water. After several seconds, the staining solution is removed, and the sections are then ready to be observed under a microscope. The anatomical orientation of the section can easily be defined without deparaffinization. By controlling the condition of sectioning procedures, we could obtain bilateral symmetrical paraffin sections containing all intended components of the visual system. This method is a rapid, simple and reliable way to get tissue sections which contain all of the multiple portions on the same plane.