Combining the gold chloride and toluidine blue stains to investigate chick embryo neural tissue

Toluidine blue and gold chloride stains are both well-known for staining nervous tissue. Toluidine blue is a general method to stain neurons and glia, used because of the speed of action. Gold sublimate is a delicate procedure that requires extreme purity of reagents and materials, and it stains astrocytes and neurons. The aim of this study was to combine these two special staining methods for embryonic neural tissue and to obtain a repeatable and easily manageable new staining method with improved overall visualization of neural tissue. Fertilized Broiler hatching eggs were incubated at 36 degrees C and on day 8 prepared for histology. Sections were cut at 7 microm thickness and slides were stained for 30 s using a 0.1% Toluidine blue solution. These slides were rinsed with dH2O followed by placing them in gold sublimate for 4 h at room temperature in the dark. Rinsing with dH2O and transferal to a 5% sodium thiosulfate solution was done, followed by another rinsing and mounting of slides. Results showed that the combination of the two methods offers a fast, reliable method with which chick embryonic neural tissue can be evaluated.