An ultracytochemical study of the nucleoplasm in meristematic plant cell (Allium porrum) interphase nuclei

In conventionally processed specimens, the nucleoplasm of plant reticulate interphase nuclei consists of a mixture of fibrils and granules of varying sizes. The degree of granularity of the nucleoplasm varies, however, with the fixative used. The finest texture of the nucleoplasm is provided by osmium tetroxide fixation, but judging by its greater transparency, material is undoubtedly extracted. In specimens fixed with glutaraldehyde only evidence of clumping of the nucleoplasm is observed. The nucleoplasm exhibits a finer, less granular texture following postfixation with osmium tetroxide. Although extraction of nucleoplasmic material is noted in samples fixed in formaldehyde, a much improved preservation is obtained when this fixative is used with osmium tetroxide. Following preservation with these two fixatives and staining en bloc with bismuth the ultrastructural characteristics of the nucleoplasm are particularly well revealed. Apart from fine fibrillar material permeating the nucleoplasmic zones, a ...