Essential Experimental Methods for Identifying Bonghan Systems as a Basis for Korean Medicine: Focusing on Visual Materials from Original Papers and Modern Outcomes

Table 2

The experimental procedure for identifying and confirming the Bonghan systems.

Stage	Target	Checkpoint	Experimental methods
			Stain	Microscopy
Identifying the BS
From the other tissues	Inside the lymphatic vessel	—	—	Stereomicroscope with a red light
	On the surfaces of the organs	Preferentially stained	Trypan blue	Stereomicroscope, light microscope
	In the brain	Preferentially stained	Hematoxylin	Stereomicroscope
	Inside the lymphatic vessel and in the brain	Preferentially stained (especially from Reissner’s fibers)	DiI	Stereomicroscope
	Inside the lymphatic vessel and on the brain	Inner fluid stained	Alcian blue	Stereomicroscope
From the artifacts	In the blood clots and the fascia	Preferentially stained	Chromium-hematoxylin	Stereomicroscope, light microscope
Confirming the BS	In the Bonghan duct	Ductules in a duct containing the rod-shaped nuclei of endothelial cells	Feulgen, acridine orange, and Janus Green B	Stereomicroscope, CLSM, SEM, and TEM
	In the Bonghan ductule	DNA stained	Feulgen, DAPI, and yoyo-1	Stereomicroscope, fluorescent microscope
	In the BS	Chromaffin substance stained	Chromium-hematoxylin	Light microscope