Asialoprotein uptake by liver cells: immunofluorescence microscopy.

Uptake of asialoproteins by hepatocytes causes a change in the intracellular pattern of immunofluorescence. Control cells display a peripheral fluorescence which probably represents nascent proteins. Dark nonfluorescent areas, that presumably contain glycogen, are located around the nucleus. In contrast, liver cells from rats injected with asialoproteins display a pancytoplasmic fluorescence due to an influx of endocytotic vesicles.     

HBsAg uptake by macrophages in vitro: An immunofluorescence study

Summary The uptake of HBsAg by in vitro cultured macrophages was studied by immunofluorescence method. Intracytoplasmic fluorescent particles appeared 3 h after the contact with HBsAg-positive serum, while after 24–48 h only a few cells contained these particles, which are probably destroyed within the cytoplasm.This work was supported by a grant of the Italian National Research Council (CNR), Progetto Finalizzato Virus.     

HBsAg uptake by macrophages in vitro: an immunofluorescence study.

The uptake of HBsAg by in vitro cultured macrophages was studied by immunofluorescence method. Intracytoplasmic fluorescent particles appeared 3 h after the contact with HBsAg-positive serum, while after 24-48 h only a few cells contained these particles, which are probably destroyed within the cytoplasm.     

Visualization of centromeric spots in the chromosomes by UV-light exposure

Summary When exposed to UV-light in the presence of Hoechst 33258, chromosomes ofAllium cepa were progressively photolyzed with increasing length of exposure; they retained their delineated contours, centromeric spots and sometimes secondary constriction bands.     

Laser-induced excitation of fluorescein isothiocyanate in the immunofluorescence

Zusammenfassung Methode für die Anregung des FITC in der Immunofluoreszenz mit Argon-Laser-Licht, die eine sehr starke Fluoreszenz ermöglicht. Diese Methode wird in dem FTA-ABS-Test für Syphilis benutzt.     

Visualization of metaphase heterochromatin inVicia faba by the denaturation-renaturation giemsa staining method

Zusammenfassung Die Denaturierungs- und Renaturierungs-Giemsafärbungsmethode auf die Metaphasenchromosomen vonVicia faba angewandt ergab heterochromatische Chromosomensegmente, die sich nach Kältebehandlung oder HCl-Essigsäure Behandlung negativ heterochromatisch verhalten und sich als die stärker Giemsa-gefärbten Segmente erweisen.     

Visualization of subcellular NAD pools and intra-organellar protein localization by poly-ADP-ribose formation

Poly-ADP-ribose polymerases (PARPs) use NAD⁺ as substrate to generate polymers of ADP-ribose. We targeted the catalytic domain of human PARP1 as molecular NAD⁺ detector into cellular organelles. Immunochemical detection of polymers demonstrated distinct subcellular NAD⁺ pools in mitochondria, peroxisomes and, surprisingly, in the endoplasmic reticulum and the Golgi complex. Polymers did not accumulate within the mitochondrial intermembrane space or the cytosol. We demonstrate the suitability of this compartment-specific NAD⁺ and poly-ADP-ribose turnover to establish intra-organellar protein localization. For overexpressed proteins, genetically endowed with PARP activity, detection of polymers indicates segregation from the cytosol and consequently intra-organellar residence. In mitochondria, polymer build-up reveals matrix localization of the PARP fusion protein. Compared to presently used fusion tags for subcellular protein localization, these are substantial improvements in resolution. We thus established a novel molecular tool applicable for studies of subcellular NAD metabolism and protein localization.