Fig. 3. Whole-mount X-Gal staining of epidermal appendices in adult (Ig)₃conalacZ mice. (A,B) Pelage (body) hair follicles. Hair (white arrow head) and follicle (black arrow head) are indicated. (A) A discrete area of the follicle is stained blue (arrow). (B) ß-galactosidase activity is also seen in the matrix of pelage hair follicles (arrow). (C) Vibrissal (whisker) follicle. X-Gal staining is found in the matrix (lower arrow) and hair shaft or inner root sheath of the vibrissal follicle (upper arrow). (D) X-Gal staining is also picked up in the bulge of this whisker follicle (arrow). Here, only a few blue cells are detected in the matrix. (E) Tail skin. Hair follicles of the tail stain blue (arrow). (F) X-Gal staining is found in the sweat glands of foot pads (arrow).