A) Anti-Fish Collagen Type I. (ns) notochordal sheath, (n) notochord. Note strong brown staining of outer part of the notochordal sheath, and absence of staining in its inner part. Mild brown staining characterizes notochordal cells and their attachment to the sheath (arrow). DAB 100x. B) Anti-Human α-Smooth Muscle Actin. (ns) notochordal sheath, (nc) notochordal cell. Strong reactivity to actin observed in the notochordal cells and their attachment to the sheath (arrows). DAB 100x. C) ß-tubulin D-10. (ns) notochordal sheath, (n) notochord, (epg) epipharyngeal groove. Notochordal sheath strongly reacts with ß-tubulin in its outer part, and mildly in its inner part. DAB 100x. D) Anti-Human Cytokeratin MNF 116. (ns) notochordal sheath, (n) notochord, (epg) epipharyngeal groove. Very strong expression of cytokeratin MNF 116 im the outer part of the notochordal sheath. DAB 100x. E) Anti-Human Vimentin. (n) notochord, (ns) notochordal sheath, (epg) epipharyngeal groove. Note strong brown staining of outer part of the notochordal sheath (arrows). DAB, 20x.