Confocal images of RALDH2 <i>(red)</i> and αSMA <i>(green)</i> expressing cells after immunolabeling with anti-RALDH2 and anti-αSMA.

<p><b>(A)</b> Low power magnification of ocular tissues demonstrating RALDH2 labeling in the retina, RPE, and choroid. <b>(B)</b> Negative control section (primary antibody pre-absorbed with recombinant RALDH2) demonstrating absence of labeling in the retina and choroid and slight auto-fluorescence in the RPE. <b>(C, D)</b> Choroid demonstrating RALDH2 labeling in extravascular cells closely associated with blood vessels and in slender cells throughout the stroma (arrowhead). <b>(E, F)</b> Double labeling of the choroid with anti-RALDH2 and anti-αSMA demonstrates RALDH2 positive cells are distinct from vascular and extravascular smooth muscle cells. Asterisk (*) indicates an αSMA-positive extravascular smooth muscle cell in (E). Upward arrow in (C-F) indicates orientation for the scleral side of the choroid tissue. Nuclei were counterstained with DAPI (<i>blue)</i>. BV, blood vessel; C, choroid; RPE, retinal pigment epithelium; ONL, outer nuclear layer; INL, inner nuclear layer; ILM, inner limiting membrane. Scale bars = 100 μm in A, B; 20 μm in C-F.