Dissection and Bulk Staining of Wool Follicles from Biopsies of Sheep Skin

Skin biopsies from sheep were fixed 2 hr in Carnoy's fluid, washed well in absolute alcohol and brought to distilled water through descending grades of alcohol. The specimens were then soaked 0.5 hr in M/15 phosphate buffer, pH 7.3, and digested at 33° C, first about 18 hr in 0.15% collagenase dissolved in pH 7.3 phosphate buffer, then washed, and finally in an equal-parts mixture of crude saliva and phosphate buffer (pH 7.3) to which 1 mg/ml ribonuclease was added. Enzymes were obtained from L. Light and Company. Staining of the washed, enzyme-treated tissue in bulk by the periodic acid-Schiff method gave differential staining of the wool follicle papilla, and separation of indvidual follicles by dissection was readily accomplished. Routine handling of large numbers of intact wool follicles is facilitated by this method.