Antibody:	anti-SPL
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS20: embryo	Present	Ubiquitous	1A	Moderate to strong expression throughout all organ systems.

Structure	Level	Pattern	Image	Note
TS23: embryo	Present	Ubiquitous	1B	Mild to moderate ubiquitous expression throughout all organs.
TS23: midbrain	Strong		1B
TS23: telencephalon	Strong	Regionally restricted	1B	Expressed in cells lining the lateral ventricle.

Structure	Level	Pattern	Image	Note
TS26: embryo	Present	Regionally restricted	1C	Expressed as a range of moderate to strong, more organ specific pattern.
TS26: liver	Weak	Regionally restricted	1C	Minimal expression in the hepatic cells.

Structure	Level	Pattern	Image	Note
TS20: embryo	Absent		1D

Structure	Level	Pattern	Image	Note
TS23: embryo	Absent		1E

Structure	Level	Pattern	Image	Note
TS28: decidua	Present		2A	Moderate to strong cytoplasmic expression.
TS12: trophectoderm	Present		2A	Weaker expression in labyrinth.

Structure	Level	Pattern	Image	Note
TS28: decidua	Present		2B	Minimal to mild cytoplasmic expression in trophoblasts.

Structure	Level	Pattern	Image	Note
TS12: primary trophoblast giant cell	Weak		2C	Absent to minimal expression.
TS12: trophectoderm	Weak		2C	Maternal endothelial cells in the labyrinth layer contain faint to weak cytoplasmic signal, and mature red blood cells within these maternal vessels are negative.

Structure	Level	Pattern	Image	Note
TS12: trophectoderm	Present		2D	Minimal to mild expression in labyrinth spongiotrophoblasts.

Structure	Level	Pattern	Image	Note
TS20: diencephalon	Strong	Regionally restricted	3A	Expressed in cells lining the third ventricle.
TS20: hindbrain	Strong	Regionally restricted	3A	Expressed in cells lining the fourth ventricle.
TS20: cerebellum primordium	Strong		3A
TS20: midbrain	Strong	Regionally restricted	3A	Expressed in cells lining the mesencephalic vesicle.
TS20: telencephalon	Strong	Regionally restricted	3A	Expressed in cells lining the telencephalic vesicle.

Structure	Level	Pattern	Image	Note
TS20: remnant of Rathke's pouch	Strong		3B

Structure	Level	Pattern	Image	Note
TS20: mandibular process	Strong		3C	Expressed in the mandibular component of the first brachial arch.

Structure	Level	Pattern	Image	Note
TS20: epidermis	Strong		3D
TS20: spinal cord	Strong		3D	Expressed in the neuroepithelium of the neural tube.

Structure	Level	Pattern	Image	Note
TS23: choroid plexus	Present		3E

Structure	Level	Pattern	Image	Note
TS23: olfactory epithelium	Present		3F	Generalized mild cytoplasmic staining, with a few multifocally scattered cells that display a strong, vacuolated cytoplasmic signal.

Structure	Level	Pattern	Image	Note
TS23: dorsal root ganglion	Present		3G

Structure	Level	Pattern	Image	Note
TS23: epidermis	Present		3H
TS23: spinal cord	Present		3H	Expressed in the neural tube.

Structure	Level	Pattern	Image	Note
TS26: spinal cord	Moderate		3I

Structure	Level	Pattern	Image	Note
TS26: olfactory epithelium	Strong		3J

Structure	Level	Pattern	Image	Note
TS26: epidermis	Strong		3K

Structure	Level	Pattern	Image	Note
TS26: hair follicle	Present		3L	Expressed in the developing pilosebaceous unit.

Structure	Level	Pattern	Image	Note
TS12: amnion	Moderate		4A
TS12: yolk sac	Moderate	Widespread	4A	Expressed in all of the columnar epithelial cells in the parietal and visceral layers.

Structure	Level	Pattern	Image	Note
TS12: blood island	Present	Regionally restricted	4B	Minimal to moderate expression in endothelial lining, and minimal positive cytoplasmic signal in fetal precursor red blood cells.

Structure	Level	Pattern	Image	Note
TS12: amnion	Moderate		4C
TS12: parietal endoderm	Moderate		4C
TS12: yolk sac	Moderate	Widespread	4C	Expressed in all of the columnar epithelial cells in the parietal and visceral layers.

Structure	Level	Pattern	Image	Note
TS20: cardiac muscle tissue	Moderate		4D
TS20: blood	Absent		4D	No staining in hematoblasts that fill vascular channels, heart chambers or liver sinusoids.
TS20: blood vessel endothelium	Present		4D	Mild to moderate cytoplasmic expression.
TS20: endocardial lining	Present		4D	Mild to moderate cytoplasmic expression.
TS20: pericardium	Present		4D	Mild to moderate cytoplasmic expression.

Structure	Level	Pattern	Image	Note
TS23: cardiac muscle tissue	Moderate		4E
TS23: blood	Absent		4E	No staining in red blood cells.
TS23: cardiovascular system endothelium	Present		4E	Mild to moderate cytoplasmic expression.
TS23: endocardial tissue	Present		4E	Mild to moderate cytoplasmic expression.
TS23: pericardium	Present		4E	Mild to moderate cytoplasmic expression.

Structure	Level	Pattern	Image	Note
TS26: cardiac muscle tissue	Absent		4F
TS26: blood	Absent		4F	No staining in red blood cells.
TS26: cardiovascular system endothelium	Weak		4F	Minimal to mild cytoplasmic expression.
TS26: endocardial tissue	Weak		4F	Minimal to mild cytoplasmic expression.
TS26: pericardium	Weak		4F	Minimal to mild cytoplasmic expression.

Structure	Level	Pattern	Image	Note
TS20: thymus primordium	Moderate		4G

Structure	Level	Pattern	Image	Note
TS23: thymus primordium	Present	Patchy	4H	Minimal scattered positive signal in lymphocytes. Mild to strong patchy positive signal in thymic epithelia cytoplasm.

Structure	Level	Pattern	Image	Note
TS26: thymus	Present	Scattered	4I	Mild to strong positive signal in thymic epithelia cytoplasm. Negative signal in lymphocytes.

Structure	Level	Pattern	Image	Note
TS20: lung epithelium	Strong		5A

Structure	Level	Pattern	Image	Note
TS20: intestine epithelium	Strong		5C , 5B	Expressed in the apical portion of epithelial cells.

Structure	Level	Pattern	Image	Note
TS23: lung epithelium	Present	Widespread	5D	Moderate to strong cytoplasmic expression throughout the tissue: the primordial bronchiolar epithelium, alveolar epithelium and pleura.

Structure	Level	Pattern	Image	Note
TS23: intestine	Weak	Regionally restricted	5F , 5E	Minimal to mild cytoplasmic expression in future submucosa, muscularis mucosa and serosa.
TS23: intestine muscularis	Weak		5E , 5F	Minimal to mild cytoplasmic expression.
TS23: intestine epithelium	Weak		5F	Mild cytoplasmic expression.

Structure	Level	Pattern	Image	Note
TS26: lung	Absent		5G

Structure	Level	Pattern	Image	Note
TS26: intestine	Weak	Regionally restricted	5H , 5I	Minimal cytoplasmic expression in developing submucosa, muscularis mucosa and serosa.
TS26: intestine epithelium	Moderate		5I	Mild cytoplasmic expression in apical cytoplasm of enterocytes.
TS26: intestine mucosa	Weak		5I
TS26: intestine muscularis	Weak		5I

Structure	Level	Pattern	Image	Note
TS12: neural fold	Present			Mild to moderate cytoplasmic expression.

Structure	Level	Pattern	Image	Note
TS20: optic stalk	Strong
TS20: liver	Present	Regionally restricted		Minimal to strong cytoplasmic expression in primordial hepatic cells. No expression in red blood cell precursors.

Structure	Level	Pattern	Image	Note
TS23: cerebral cortex	Strong			Expressed in neopallial cortex.
TS23: retina	Strong
TS23: trigeminal ganglion	Strong
TS23: hindbrain	Strong	Regionally restricted		Expressed in cells lining the fourth ventricle.
TS23: cartilage	Present			Mild to moderate cytoplasmic expression in chondrocytes.
TS23: pancreas	Weak			Minimal to mild cytoplasmic expression.
TS23: liver	Present	Regionally restricted		Minimal to strong cytoplasmic expression in primordial hepatic cells. No expression in red blood cell precursors.

Structure	Level	Pattern	Image	Note
TS26: cartilage	Weak			Minimal to mild cytoplasmic expression in chondrocytes.
TS26: thyroid gland	Weak	Regionally restricted		Minimal cytoplasmic expression in developing follicular cells.