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  • 1970-1974  (15)
  • 1920-1924  (1)
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  • 1
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Zur quantitativen Bestimmung der Feulgen-DNS-Mengen wurden Leberzellkerne mit Acriflavin fluorochromiert. Durch fluoreszenzmikrospektrographische Untersuchung konnte gezeigt werden, daß die Meßergebnisse nicht durch Metachromasie beeinträchtigt werden. Bei der Photodekomposition kommt es zu keiner Verschiebung der relativen spektralen Intensitätsverteilung. Die Histogramme der Feulgen-DNS-Mengen von di- und tetraploiden Leberzellen zeigen die exakte Einhaltung der Ploidiestufen und eine geringe Streuung der Meßwerte.
    Notes: Summary For the purpose of quantitative determination of Feulgen-DNA liver nuclei had been stained with fluorescent Schiff-type dye Acriflavin according to Böhm and Sprenger (1968). Fluorescence microspectrophotometric investigations revealed that the quantitative measuring results are not falsified by metachromasia and that photofading does not cause a shift in the relative spectral distribution of fluorescence intensity. The Feulgen-DNA histograms of di- and tetraploid liver nuclei confirm the accuracy of quantitative measurements by exact reproduction of ploidy classes and low variation range in each class.
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  • 2
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ausgehend vom Leitz-Mikrospektrographen wird gezeigt, wie dieses Gerät für mikrospektrofluorimetrische Untersuchungen und für die quantitative Fluoreszenzcytophotometrie ausgerüstet werden kann. Die im Zusammenhang mit der Anwendung des Gerätes auftretenden Fragen der Eichung und Korrektur der Spektralkurven werden erörtert.
    Notes: Summary The use and additional equipment of the Leitz-Mikrospectrograph for microspectrofluorometry and fluorescence cytophotometry are described in detail. Fluorescence excitation with incident light together with the use of dichromatic beam splitters for optimum separation of the excitation beam from emitted radiation are the characteristic features of this instrument. The fluorescence light is spectrally dispersed by a glass-prism (Special glass for visible light, quarz for UV). A motor driven oscillating mirror moves along the spectrum and reflects the light of continuously changing wavelength on to the photo-cathode of the multiplier, that transfers the optical impulse into an electrical signal. The wavelength dependend change of spectral intensity is registered by a light beam oscillograph fitted with four fixed potentiometers indicating the 400, 500, 600 and 700 nm wavelength position by crosspoints with an oblique line drawn by the wavelength potentiometer, while the sixth potentiometer records the spectral curve. Problems of spectral calibration and correction are discussed. When the prism and the oscillating mirror are removed the instrument may be used as fluorescence cytophotometer. For this purpose of quantitative fluorescence cytophotometry a digital measuring unit with a print-out instrument is presented.
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  • 3
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ausgehend vom Leitz-Mikroskopphotometer MPV mit Auflicht-Anregung wird ein Durchflußfluorescenzcytophotometer beschrieben, das es gestattet, die relativen Feulgen-DNS-Mengen von bis zu 1000 Zellen pro Sekunde zu bestimmen. Die Meßwerte werden in einem Impulshöhenanalysator klassifiziert und gespeichert. Auf Abruf wird der Speicherinhalt analog als Histogramm ausgeschrieben oder digital als Zahlenfolge ausgedruckt. Das Vorgehen bei der Zellsuspensionsherstellung, Fixierung, Hydrolyse und Färbung mit dem Feulgen-Farbstoff Akriflavin wird dargelegt. Anwendungsbeispiele werden besprochen.
    Notes: Summary A flow-through cytophotometer based upon the Leitz-microscope photometer (MPV) is described. The light source is a high pressure Xenon arc HBO 100 in an arrangement for epiillumination. The flow system is designed in such a way that each cell, after previous Feulgenstaining in aqueous suspension, has to pass through the focal plane of the objective. This is achieved by a self-constructed flow channel with a vertical fluid stram carrying the stained cells along the optical axis of the microscope at a flow rate of 100 to 1000 cells per sec. After passage through the focal plane with simultanneous registration of the highest fluorescence reading the cells are flushed off by a horizontal water current. The fluorescence light impulses emitted by the cells are classified and stored by an impulse height discriminator, from which they may be recalled either analogically as a histogram (DNA distribution pattern) or digitally as a series of numbers. In addition, the fluorescence impulses can be visualized at the screen of an oscillograph. The flow rate of the fluorochromized cells is determined by means of a counter unit. The steps of preparation of the cell suspension as well as fixation, hydrolysis and Feulgen-staining with acriflavine-Schiff of the suspended tissue cells is described in detail. The possibilities of application of the instrument as a cyto-morphometric approach to cytology and cytochemistry automation are discussed.
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  • 4
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Akriflavin-Feulgen-Färbung (Böhm und Sprenger, 1968) und die Ethidiumbromid-Fluorochromierung nach vorausgehender Pepsinbehandlung (Göhde et al., 1971) ergeben an Leberzellausstrich-Präparaten weitgehend gleichartige DNS-Häufigkeitsverteilungen. Bei der zeitlich aufwendigen (220 min) Akriflavin-Färbung ist eine optimale Darstellung der Zellmorphologie und eine jahrelange Archivierung der Ausstrichpräparate möglich. Die rasch durchführbare Ethidiumbromid-Färbung (70 min) bietet nur nach schwerer Alteration der Zellmorphologie durch die vorausgehende Pepsinbehandlung eine selektive Darstellung der DNS. Eine Archivierung von Ausstrichpräparaten ist nur für 2 Tage möglich. Die schwere Alteration der Zellmorphologie ist besonders bei durchflußphotometrischen Prescreeninguntersuchungen in der gynäkologischen Krebsvorsorge nachteilig. Zellpopulationen, die zu einer zytophotometrischen Verdachtsdiagnose geführt haben, sind durch Verlust des Zytoplasmas und der Kernstruktur einer konventionellen morphologischen Diagnostik nicht mehr zugängig.
    Notes: Summary Acriflavine-Feulgen (Böhm und Sprenger, 1968) and ethidiumbromide fluorescence after previous pepsin digestion (Göhde et al., 1971) yield corresponding DNA distribution patterns when applied to liver smears. With the time-consuming acriflavine staining (220 min) the cellular morphology is best preserved and the stained specimen may be stored for long periods. The rapidly obtainable ethidiumbromide staining (70 min) results in a selective fluorescence of DNA only after heavy alteration of the cellular morphology by pepsin digestion. Storage of the material is only possible for two days. The heavily altered cellular morphology, however, is rather unfavorable for prescreening in automated cytology. Specimens that were found to be suspicious are no longer suitable for conventional cytological diagnosis, because they have lost their cytoplasm and nuclear chromatin structure.
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  • 5
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A sensitive test is described for proof of even illumination of the light field as well as a steady surface response of the photocathode in fluorescence cytophotometry using a GG 21 uranyl glass platelet as fluorescence standard.
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  • 6
    ISSN: 1433-8491
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1420-9039
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A strong immunological crossreactivity between the extracts of the albumin gland of snails (Helix pomatia) and the content of snail eggs is described, suggesting that the former supplies the eggs with protective substances (agglutinins, protease-inhibitors).
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  • 9
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
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