Antibody:	anti-CD34 (RAM34)
Detection system:	Biotinylated secondary antibody/[Strept]avidin

Structure	Level	Pattern	Image	Note
TS13: dorsal aorta	Present		2A
TS13: primary head vein	Ambiguous		2A	Barely detectable.

Structure	Level	Pattern	Image	Note
TS13: dorsal aorta	Present	Regionally restricted	2B	Expressed in the endothelium.

Structure	Level	Pattern	Image	Note
TS13: dorsal aorta	Strong	Regionally restricted	2C	Expressed in the endothelium.
TS13: blood	Present		2C
TS13: posterior cardinal vein	Absent		2C
TS13: gut	Weak	Regionally restricted	2C	Expressed in dorsal gut epithelium.

Structure	Level	Pattern	Image	Note
TS13: dorsal aorta	Strong	Regionally restricted	2D	Expressed in the endothelium.
TS13: trunk mesenchyme	Present		2D
TS13: neural tube	Weak		2D
TS13: blood	Present	Regionally restricted	2D	Expressed in blood cells in the aortic lumen.

Structure	Level	Pattern	Image	Note
TS16: dorsal aorta	Present	Regionally restricted	2E	Expressed in the endothelium.
TS16: trunk mesenchyme	Strong	Regionally restricted	2E	Expressed in discrete rounded cells in mesenchyme adjacent the dorsal aorta.
TS16: posterior cardinal vein	Absent		2E
TS16: gut dorsal mesentery	Strong	Regionally restricted	2E	Expressed in presumed hematopoietic progenitor cells.

Structure	Level	Pattern	Image	Note
TS16: dorsal aorta	Strong	Regionally restricted	2F	Expressed in the endothelium, in presumed hematopoietic progenitor cells attached to the aortic endothelium at the level of the mesonephros.
TS16: trunk blood vessel	Present	Regionally restricted	2F	Expressed in many small vessels within the nephrogenic mesenchyme, and capillary sprouts of the posterior cardinal veins.

Structure	Level	Pattern	Image	Note
TS16: trunk blood vessel	Strong	Regionally restricted	2G	Expressed in precapillary sprouts surrounding the tracheal diverticulum and, to a lesser extent, the oesophagus.

Structure	Level	Pattern	Image	Note
TS13: blood	Present		2H
TS13: allantois blood vessel	Present	Regionally restricted	2H	Expressed in the walls and prevascular mesenchyme.

Structure	Level	Pattern	Image	Note
TS16: liver	Present	Regionally restricted	2I	Expressed in hematopoietic cells but not on the endothelium of the sinusoids.

Structure	Level	Pattern	Image	Note
TS12: yolk sac endoderm	Present		4A
TS12: yolk sac mesenchyme	Weak		4A	Expressed in the mesodermal layer between two blood islands.
TS12: blood island	Present	Regionally restricted	4A	Largely confined to flattened cells around the periphery (vascular endothelium).

Structure	Level	Pattern	Image	Note
TS12: yolk sac endoderm	Present		4B
TS12: blood island	Present	Regionally restricted	4B	Expressed in scattered cells around the periphery of the blood islands.

Structure	Level	Pattern	Image	Note
TS13: yolk sac endoderm	Present		4C
TS13: blood island	Present	Regionally restricted	4C	Expressed in cells around the periphery of the blood islands.
TS13: allantois blood vessel	Present	Regionally restricted	4C	Expressed in small blood vessels.
TS13: allantois mesenchyme	Absent		4C	Not expressed in the hematopoietic cells nor in the allantoic mesenchyme.

Structure	Level	Pattern	Image	Note
TS13: vitelline blood vessel	Present		4D	Expressed in the endothelium.
TS13: blood	Present		4D	hematopietic cells

Structure	Level	Pattern	Image	Note
TS14: yolk sac blood vessel	Present	Regionally restricted	4E	Less prominent staining in the vascular endothelium.
TS14: blood	Strong		4E	hematopietic cells
TS14: vitelline blood vessel	Present	Regionally restricted	4E	Expressed in the endothelium of the vitelline capillaries.

Structure	Level	Pattern	Image	Note
TS16: yolk sac blood vessel	Present	Regionally restricted	4F	Expressed in the endothelium.

Structure	Level	Pattern	Image	Note
TS16: vitelline artery	Present	Regionally restricted	4G	Expressed in the endothelium.
TS16: yolk sac mesenchyme	Present	Regionally restricted	4G	Expressed in proximal portion of the vitelline artery, possible haematopoietic activity.

Structure	Level	Pattern	Image	Note
TS16: umbilical artery	Present	Regionally restricted	4H	Expressed in the endothelium and thickened, possibly haematopoietic region.

Structure	Level	Pattern	Image	Note
TS12: dorsal aorta	Present

Structure	Level	Pattern	Image	Note
TS12: dorsal aorta	Present			Increased expression.
TS12: 1st arch artery	Present
TS12: outflow tract	Present

Structure	Level	Pattern	Image	Note
TS13: artery	Strong	Regionally restricted		Expressed in the intersomitic and vertebral arteries.
TS13: anterior cardinal vein	Absent
TS13: common cardinal vein	Absent

Structure	Level	Pattern	Image	Note
TS14: gut dorsal mesentery	Strong	Regionally restricted		Expressed in presumed hematopoietic progenitor cells.
TS14: dorsal aorta	Strong	Regionally restricted		Expressed in presumed hematopoietic progenitor cells attached to the aortic endothelium at the level of the mesonephros.

Structure	Level	Pattern	Image	Note
TS16: trunk blood vessel	Present	Regionally restricted		Expressed in capillary sprouts invading the neuroepithelium of the spinal cord.
TS16: head blood vessel	Present	Regionally restricted		Expressed in capillary sprouts invading the neuroepithelium of the brain.