ACRIDINE ORANGE FLUOROCHROMING AND ULTRAVIOLET ABSORPTION OF STAPHYLOCOCCUS AUREUS CELLS MODIFIED BY UNBALANCED NUCLEIC ACID AND CELL WALL SYNTHESIS

1966 ◽  
Vol 12 (4) ◽  
pp. 677-682
Author(s):  
Jacques de Repentigny ◽  
Sorin Sonea ◽  
Armand Frappier
Keyword(s):  
Staphylococcus Aureus ◽  
Nucleic Acid ◽  
Fluorescence Microscopy ◽  
Nucleic Acids ◽  
Acridine Orange ◽  
Dry Weight ◽  
Cellular Level ◽  
Cellular Heterogeneity ◽  
Nucleic Acid Content ◽  
Bacterial Populations

Cultures of Staphylococcus aureus were grown in the presence of five different antimetabolites (5-fluorodeoxyuridine, aminopterin, 8-azaguanine, mitomycm-C, 5-fluorouracil) active against ceil walls and (or) nucleic acids. Fluorescence microscopy of smears stained with acridine orange revealed reddish and green cells in both treated and untreated cultures. There were less than 20% of reddish cells in untreated cultures and more than 40% in treated cultures. Treated cultures contained fewer viable organisms. All antimetabolites except mitomycin-C produced a diminution in the nucleic acids, chemically determined as percentage of dry weight of bacteria. Only 5-fluorouracil increased the RNA/DNA ratio. However, with ultraviolet microscopy at 260 mμ wavelength the absorption of reddish cells is much higher than that of the green cells, which, at the cellular level, seemed to indicate a greater nucleic acid content. With ultraviolet or with fluorescence microscopy we have obtained similar evidence of the cellular heterogeneity produced by antimetabolites in bacterial populations.

Changes in the nucleic acid content of the uterus of sheep during involution following ovariectomy and following oestrogenic stimulation

1976 ◽  
Vol 27 (5) ◽  
pp. 669 ◽  
Author(s):  
DA Little ◽  
LJ Lambourne
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Total Content ◽  
Mean Value ◽  
Nucleic Acid Content ◽  
Uterine Tissue ◽  
Rna Concentration

The concentrations of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), in ovine uterine tissue were studied to determine whether the ratio RNA/DNA might be used in the bioassay of oestrogenic activity. As the uterus decreased in size with time after ovariectomy, the concentration of DNA increased markedly, but the total content of DNA in the uterus remained constant (mean value 342 ? 8 (SE) mg). The RNA concentration of the tissue decreased during involution, with the result that a highly significant reduction of 33% in the RNA/DNA ratio occurred within 2 weeks of ovariectomy. The ratio decreased further with time. Other ewes were treated for 3 days with diethylstilboestrol dipropionate (10 µg/day), commencing 2 weeks after ovariectomy; the stage of the oestrous cycle at which the ovaries were removed had no effect on the response to the oestrogen. Changes in the nucleic acid concentrations in the uteri of these ewes, and the results obtained during involution, indicate that the RNA/DNA ratio of uterine tissue in ovariectomized ewes has potential as a basis for the bioassay of materials of low oestrogenic potency.

scholarly journals Studies on the Nucleic Acids of the Malaria Parasite, Plasmodium Berghei (Vincke & Lips)

1953 ◽  
Vol 6 (2) ◽  
pp. 234 ◽  
Author(s):  
PR Whitfeld
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Red Blood Cells ◽  
Plasmodium Berghei ◽  
Acid Content ◽  
Blood Cells ◽  
Malaria Parasite ◽  
Nucleic Acid Content ◽  
Solid Residue ◽  
Parasite Plasmodium

Changes in� the nucleic acid content of the solid residue obtained by haemolysing the blood of mice infected with Plasmodium berghei have been examined. The residue from blood in which 25 per cent. of the red blood cells were parasitized contained 20-25 times as much ribosenucleic acid (RNA) and 12 times as much desoxyribosenucleic acid (DNA) as the residue from uninfected blood.

scholarly journals Characteristics and Dynamics of Bacterial Populations during Postantibiotic Effect Determined by Flow Cytometry

1998 ◽  
Vol 42 (5) ◽  
pp. 1005-1011 ◽  
Author(s):  
Magnús Gottfredsson ◽  
Helga Erlendsdóttir ◽  
Ásbjörn Sigfússon ◽  
Sigurdur Gudmundsson
Keyword(s):  
Flow Cytometry ◽  
Nucleic Acid ◽  
Fluorescence Microscopy ◽  
Acid Content ◽  
Quantitative Information ◽  
Nucleic Acid Content ◽  
Dependent Manner ◽  
Postantibiotic Effect ◽  
E Coli ◽  
Drug Removal

ABSTRACT Changes in bacterial ultrastructure after antibiotic exposure and during the postantibiotic effect (PAE) have been demonstrated by electron microscopy (EM). However, EM is qualitative and subject to individual interpretation. In contrast, flow cytometry gives qualitative and quantitative information. The sizes and nucleic acid contents of Escherichia coli and Pseudomonas aeruginosa were studied during antimicrobial exposure as well as during the PAE period by staining the organisms with propidium iodide and analyzing them with flow cytometry and fluorescence microscopy. The effects of ampicillin, ceftriaxone, ciprofloxacin, gentamicin, and rifampin were studied for E. coli, whereas for P. aeruginosa imipenem and ciprofloxacin were investigated. After exposure of E. coli to ampicillin, ceftriaxone, and ciprofloxacin, filamentous organisms were observed by fluorescence microscopy. These changes in morphology were reflected by increased forward light scatter (FSC) and nucleic acid content as measured by flow cytometry. For the β-lactams the extent of filamentation increased in a dose-dependent manner after drug removal, resulting in formation of distinct subpopulations of bacteria. These changes peaked at 20 to 35 min, and bacteria returned to normal after 90 min after drug removal. In contrast, the subpopulations induced by ciprofloxacin did not return to normal until >180 min after the end of the classically defined PAE. Rifampin resulted in formation of small organisms with low FSC, whereas no distinctive characteristics were noted after gentamicin exposure. For P. aeruginosa an identifiable subpopulation of large globoid cells and increased nucleic acid content was detected after exposure to imipenem. These changes persisted past the PAE, as defined by viability counting. Swollen organisms with increased FSC were detected after ciprofloxacin exposure, even persisting during bacterial growth. In summary, for β-lactam antibiotics and ciprofloxacin, the PAE is characterized by dynamic formation of enlarged cell populations of increased nucleic acid content, whereas rifampin induces a decrease in size and nucleic acid content in the organisms. Flow cytometry is an ideal method for future studies of bacterial phenotypic characteristics during the PAE.

Observations on the Chromatin Staining by Aluminium-Hematoxylin

1979 ◽  
Vol 34 (12) ◽  
pp. 1285-1286 ◽  
Author(s):  
Juan C. Stockert
Keyword(s):  
Ionic Strength ◽  
Nucleic Acid ◽  
Acridine Orange ◽  
Ethidium Bromide ◽  
Acid Content ◽  
High Ionic Strength ◽  
Nucleic Acid Content ◽  
Staining Reaction ◽  
Intense Staining ◽  
Chromatin Fluorescence

Abstract The staining reaction of chromatin by aluminium -hematoxylin was investigated. Intense staining, which proved dependent on nucleic acid content, was achieved by using either the preformed lake, mordanting followed by hematoxylin, hematoxylin alone or the lake at high ionic strength. Extraction procedures removed aluminium ions from chromatin but the lake was retained. Chromatin fluorescence induced by ethidium bromide and acridine orange was abolished after staining with the lake. Intercalating-like forces are suggested for aluminium -hematoxylin binding to chromatin.

Possible mechanism of gibberellin-induced chlorosis in lettuce seedlings

1973 ◽  
Vol 51 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Gaurangakumar Das
Keyword(s):  
Nucleic Acid ◽  
Protein Content ◽  
Sugar Content ◽  
Dry Weight ◽  
Weight Basis ◽  
Nucleic Acid Content ◽  
Chlorophyll B ◽  
Lactuca Sativa L ◽  
Grand Rapids ◽  
Rna And Dna

Effects of gibberellin A3 (GA) on growth, pigments, protein, and nucleic acid content of the cotyledons of lettuce seedlings (Lactuca sativa L. cv. Grand Rapids) are reported. GA treatment increased both the total shoot and cotyledon fresh weights, and decreased chlorophyll content per cotyledon and on a dry weight basis. GA also decreased the protein content of the cotyledon, but increased the level of RNA and DNA measured on a dry weight basis. The hormone had no effect on the pheophytin: chlorophyll ratio, but increased the ratios of chlorophyll a: chlorophyll b, phytol: chlorophyll, and carotene: chlorophyll. GA also increased the sugar content of the cotyledons. Treatment of excised cotyledons with glucose had an effect similar to that of GA on chlorophyll and protein content. The data are discussed in relation to the mechanism of GA-induced chlorosis.

BLOAT INVESTIGATIONS. STUDIES ON SOLUBLE PROTEINS AND NUCLEIC ACIDS IN BLOATING AND NONBLOATING FORAGES

1969 ◽  
Vol 49 (1) ◽  
pp. 69-75 ◽  
Author(s):  
J. M. McArthur ◽  
J. E. Miltimore
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Total Protein ◽  
Acid Content ◽  
Soluble Proteins ◽  
Nucleic Acid Content ◽  
Total Proteins ◽  
Agar Gel ◽  
Forage Mixtures

The soluble proteins in five bloating and six nonbloating forages were separated chromatographically on agar gel columns and 18S protein, the agent causing bloat, was determined in column effluents. Bloating forages contained approximately one-third of total proteins in the form of 18S; nonbloating forages one-sixth or less. Total protein was highest in bloating forages. Nucleic acid content of the two types of forages was not significantly different. Production of nonbloating forage mixtures by mixing forages of high and low 18S protein is discussed.

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