A new banding technique of rat (Rattus norvegicus) chromosomes

Abstract

VERNOLE, P., NERI, G. and SERRA, A. 1984. A new banding technique of rat (Rattus norvegicus) chromosomes.—Hereditas 101:199–204. Lund, Sweden. ISSN 0018–0661. A technique is described for visualizing, alternatively, early or late replicating bands in rat chromosomes. It consists of 5-BrdU incorporation into the chromosome DNA at different periods of the cell cycle, followed by treatment of the chromosomes with the fluorochrome Hoechst 33258, photolysis by sunlight or U.V. light, heat denaturation and Giemsa staining. Consistent, sharp bands were obtained. Those which are darkly stained after early incorporation of 5-BrdU correspond almost exactly to G bands and are late replicating bands (L.R.); those which stain darkly after late incorporation of 5-BrdU show a reverse pattern (R bands) and are early replicating bands (E.R.). This is the first description of R bands in the rat.