The Relation Between the Staining Properties of the Thyroidal Colloid and Its Iodine Content

A new staining technique has been developed for the thyroid gland involving the use of two components of the Mallory connective tissue stain, aniline blue and orange G in reversed proportions.Various indices such as incorporation of radioiodine, epithelial cell height, and number of blue and yellow staining follicles and total number of follicles have been used to test the validity of the color reaction in the colloid. The comparison of these diverse indices strongly suggests that the colloid material which stains with aniline blue corresponds to iodinated thyroglobulin, while the yellow staining material appears to be devoid of biologically active iodinated amino acids.