Antibody:	anti-fibulin 1 (Rb1323)
Detection system:	Secondary antibody coupled to fluorescein
Assay notes:	Fixative was 2% or 4% paraformaldehyde.

Structure	Level	Pattern	Image	Note
TS15: endocardial cushion	Present	Regionally restricted	4E	Expression is in the extracellular matrix of cardiac cushion mesenchymal cells.
TS15: endocardial lining	Weak		4E
TS15: cardiac muscle tissue	Trace		4E	Little or no staining.

Structure	Level	Pattern	Image	Note
TS17: atrioventricular canal	Present	Regionally restricted	5G	Expression is in the extracellular matrix within the mesenchymal core of the atrioventricular canal cushions.
TS17: endocardial lining	Weak	Regionally restricted	5G	Expression is in the extracellular matrix associated with the endocardium.

Structure	Level	Pattern	Image	Note
TS17: outflow tract	Present

Structure	Level	Pattern	Image	Note
TS20: atrioventricular endocardial cushion	Strong	Regionally restricted	6H , 6G	Staining is in the extracellular matrix of the cushion core mesenchyme, lower levels within the intercellular spaces in the zone of densely packed cells.

Structure	Level	Pattern	Image	Note
TS22: heart valve	Present	Regionally restricted	7G , 7H	Expression is in the extracellular matrix of mesenchymal cells within the elongated portion of the atrioventricular leaflets.