A Note on the Transplantability of Organ- Cultured Normal Mouse Mammary Tissues 1. 2

SUMMARY-Normal prelactating mammary tissues from C3H/Crgl and A/Crgl female mice were cultured for 3, 5, or 15 days in media with no, minimal, or complete (secretion-inducing) hormone supplementation. His-tological integrity proved a poor indicator of subsequent development after transplantation: Disorganized and necrotic explants grew as well as those maintained in culture in an active secretory condition.-J Nat Cancer Inst 40: 1267-1271, 1968. ALTHOUGH PRENEOPLASTIC mammary tis-sues (primary hyperplastic alveolar nodules and outgrowths derived from them) from mice have been successfully transplanted after various periods in organ culture (1-3), observations on the survival and growth potential of comparable normal tissues are lacking. The present note reports on the survival and subsequent transplantability of organ-cultured explants of prelactating mammary tissue. MATERIALS AND METHOD