Staining of the Reinke crystalloids in the human testis--re-evaluation study

Reinke crystalloid (CR)s are rod or corn shaped structures present in the interstitial cells (Leydig cell) of human testis. Due to existing controversies and because of their importance in histological studies, we decided to reevaluate their staining behavior with various dyes. Earlier it has been shown that hematoxylin and eosin dyes do not stain CRs even though their protein nature remains undisputed. In the present study, sections of testicular tissues embedded in glycol-methacrylate (GMA) showed that hematoxylin binds to CRs non-specifically and eosin stains them specifically. The reasons for stainability and/or non stainability of CRs with hematoxylin, eosin and other dyes are discussed.