ISSN:1052-0295    

DOI:10.3109/10520299509108198

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

DAPI (4′,6-diamidino-2-phenylin-dole) is a DNA-specific probe which forms a fluorescent complex by attaching in the minor grove of A-T rich sequences of DNA. It also forms nonfluorescent intercalative complexes with double-stranded nucleic acids. The physicochemical properties of the dye and its complexes with nucleic acids and history of the development of this dye as a biological stain are described. The application of DAPI as a DNA-specific probe for flow cytometry, chromosome staining, DNA visualization and quantitation in histochemistry and biochemistry is reviewed. The mechanisms of DAPI-nucleic acid complex formation including minor groove binding, intercalation and condensation are discussed.

ISSN:1052-0295    

DOI:10.3109/10520299509108199

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

A flow cytometric method has recently been developed using biotinylated dUTP (b-dUTP) in a reaction catalyzed by terminal deozynucleotidyl transferase (TdT) to identify the endonuclease-induced DNA strand breaks occurring during apoptosis. Counterstaining of DNA makes it possible to relate apoptosis to cell cycle position or DNA index. In the present study, we compared this method with one using digoxigenin-conjugated dUTP (d-dUTP) to label apoptotic cells. The discrimination of apoptotic from nonapoptotic cells was similar when incorporation of d-dUTP was compared with b-dUTP. Both techniques resulted in a 20–30 fold increase in staining of apoptotic over nonapoptotic cells although somewhat less background fluorescence was observed with the d-dUTP. Direct labeling with fluo-resceinated dUTP (f-dUTP) was less sensitive in detecting DNA strand breaks, but had the advantage of simplicity. The principle of labeling DNA strand breaks using TdT was also employed to identify DNA replicating cells. To this end, the cells were incubated in the presence of BrdUrd, then exposed to UV light to selectively photolyse DNA containing the incorporated BrdUrd. DNA strand breaks resulting from the photolysis were then labeled with b-dUTP or d-dUTP. This approach is an alternative to immunocytochemical detection of BrdUrd incorporation, but unlike the latter does not require prior DNA denaturation, thus can be applied when the denaturation step must be avoided. The method was sensitive enough to recognize DNA synthesizing cells that were incubated with BrdUrd for only 5 min, the equivalent of replication of less than 1% of the cell's genome. The discrimination between apoptotic vs. BrdUrd incorporating-cells is based on different extractability of DNA following cell fixation. This method can be applied to analyze both cell proliferation (DNA replication) and death (by apoptosis) in a single measurement.

ISSN:1052-0295    

DOI:10.3109/10520299509108200

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Fluorogenic substrates can detect enzymatic activity associated with cells. It is difficult, however, to detect activity within a single cell or in an organelle since hydrolytic substrates yield products that rapidly leak from the cell. Several new solutions are presented including trapping the fluorescent product in membranes, in cell organelles, or as a glutathione conjugate. Novel substrates also are described that directly yield highly fluorescent precipitates at the site of enzymatic activity. These can be used for detecting endogenous activity in cells or for enzyme-amplified histochemical detection. Some of these substrates can be used in live cells.

ISSN:1052-0295    

DOI:10.3109/10520299509108201

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

We investigated immunocytochemical staining of microtubular cytoskeleton of free nuclear endosperm, a tissue which is particularly difficult to fix. This tissue requires fixation for 45 hr to preserve the integrity of the microtubular network after paraformaldehyde based fixation. Low glutaraldehyde concentration in the fixative and the ethanol dehydration retainsβ-tubulin antigenicity and the former improves preservation of tissue structure. An ethanol-free embedding method is recommended for immunocytochemical studies of ethanol sensitive target proteins.

ISSN:1052-0295    

DOI:10.3109/10520299509108202

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Ammonium vanadate can act as both an oxidant and a mordant for hematoxylin. Lithium carbonate can remove vanadate hematoxylin from other structures so that only the most basic proteins are stained. Brief diazotization of the tissue sections restricts staining to the histone proteins of the nucleus.

ISSN:1052-0295    

DOI:10.3109/10520299509108203

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Onion (Alliumcepa)root tips were fixed in a proprietary solution without aldehyde, toxic metals or acetic acid. Fixed specimens were embedded in paraffin, sectioned on a rotary microtome and mounted on detergent-washed slides without adhesive. Slides with ribbon segments affixed were immersed in 0.2% aqueous alcian blue 8GX in screw-capped Coplin jars in a water bath at 50 C for 1 hr. Excess alcian blue was rinsed off under cold running tap water and the slides were immersed in quick-mixed hematoxylin at room temperature for 15 min. Stained slides were deparaffinized, rinsed with isopropanol, air dried, and coverslips were affixed with resin. Thus, the traditional paraffin microtechnique has been modified at all steps from fixation to finishing slides with coverslips.

ISSN:1052-0295    

DOI:10.3109/10520299509108204

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Azure B-eosin APAAP staining allows simultaneous analysis of peripheral blood and bone marrow cells for hematological characteristics and immunological cell marker profiles. A defined sequence of staining procedures maintains characteristic components of the Romanowsky-Giemsa stain whereas cell antigens can be detected immunologically using the alkaline phosphatase-anti-alkaline phosphatase (APAAP) detection system. Antigens are visualized by the staining product of the substrate-naphthol AS GR phosphate and variamine blue salt. The usefulness of the azure B-eosin APAAP method was demonstrated on blood and bone marrow smears of patients with various hematological disorders.

ISSN:1052-0295    

DOI:10.3109/10520299509108205

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Megakaryocytes from normal persons and from patients with immune thrombocytopenic purpura, myelodysplastic disorders, Hypersplenism, and essential thrombocythemia displayed vivid magenta metachromatic staining of the cytoplasm when stained with basic black MSP followed by brief exposure to dilute hydrochloric acid. Under the same conditions, other hematopoietic cells were completely decolorized. Acid fast metachromasia of megakaryocytes facilitates their identification, particularly in cases of small and atypical megakaryocytes found in disease states.

ISSN:1052-0295    

DOI:10.3109/10520299509108206

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor