Intracellular localization of actin in cultured fibroblasts by electron microscopic immunocytochemistry.

Localization of nucleolar chromatin by immunocytochemistry and in situ hybridization at the electron microscopic level.

Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well as the definition of nucleolar structures in which enzymes of the rDNA transcription machinery reside have been investigated in mammalian cells by various immunogold labelling approaches at the...

Immunocytochemistry at the Electron-Microscopic Level

Localization of RNA polymerase I in interphase cells and mitotic chromosomes by light and electron microscopic immunocytochemistry.

Rabbit antibodies to RNA polymerase I from a rat hepatoma have been used to localize the enzyme in a variety of cells at the light and electron microscopic level. In interphase cells the immunofluorescence pattern indicated that polymerase I is contained exclusively within the nucleolus. That this fluorescence, which appeared punctated rather than uniform, represented transcriptional complexes ...

Intracellular accumulation of azithromycin by cultured human fibroblasts.

Azithromycin was shown to achieve high concentrations in human skin fibroblasts. Intracellular penetration occurred rapidly (10 micrograms/mg of cellular protein after 3 h) and then increased progressively over a 3-day period; azithromycin accumulated up to 21 times more than erythromycin (61.1 versus 2.9 micrograms/mg of protein). Uptake was dependent on the extracellular concentration, was in...

Metabolism and intracellular localization of a fluorescently labeled intermediate in lipid biosynthesis within cultured fibroblasts

In this paper we report on the uptake and distribution of an exogenously supplied fluorescent phosphatidic acid analogue by Chinese hamster fibroblasts. Under appropriate in vitro incubation conditions, 1-acyl-2-(N-4-nitrobenzo-2-oxa-1,3-diazole)-aminocaproyl phosphatidic acid was rapidly and preferentially transferred from phospholipid vesicles to cells at 2 degrees C. However, unlike similar ...