Chromosome delineation induced by a combined potassium permanganate-sodium bisulfite treatment

A cytological procedure for in vitro chromosome delineation has been studied using human and mouse (Mus musculus) chromosomes. This method, consisting of slide incubation in KMnO4 at 0--5 degrees C for 24 h followed by a short exposure to NaHSO3 (1--3 min) and Giemsa staining, induces extraction of chromatin from human and mouse interphase nuclei and chromosomes. Autoradiography after 3H-ThD incorporation in vitro and cytophotometry confirmed that DNA is removed. Well contour-delineated and non-distorted chromosomes are observed in both species allowing the identification of all human chromosome groups. Contour chromosome delineation and its relationship to chromosome organization is briefly discussed.