Photometrie measurements of grain density in autoradiographs

Rogers, Alisdair

doi:10.1111/j.1365-2818.1972.tb04652.x

Cited by 31 publications

(18 citation statements)

References 7 publications

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“…The emulsion was left to gel and dry completely for 30 min. This gave a monolayer of silver bromide grains, shown by the interference colour (Rogers, 1979) and on examination in a transmission electron microscope.…”

Section: On Artificial Surfacesmentioning

confidence: 99%

“…After exposure, slides were thawed for 1 h and then developed in Kodak D.19 for 2 min at 293 K. They were rinsed in deionized water for 30 s, placed in a stop-bath of acetic acid (1 % w/v) for 10 s, rinsed in deionized water for 30 s, and fixed in buffered (pH 7.0) sodium thiosulphate solution (30% w/v) for 3 min or double the time taken for the emulsion to become clear. The fixed slides were rinsed for 1 min in each of three baths of deionized water (method adapted from Rogers, 1979). The autoradiographs were air-dried, stained with Neutral Red and airdried again; the filters were cleared for microscopic examination using immersion oil (Cargille Type A).…”

Section: On Artificial Surfacesmentioning

confidence: 99%

“…Counting silver grains on autoradiographs is a laborious and time-consuming process, and so in later experiments a microscope photometer was used. Various techniques have been devised for photometry of autoradiographs (Rogers, 1979). The most commonly used system is reflected light photometry, in which polarized incident light is directed on to the specimen through the microscope objective lens, and the light reflected by the silver grains (Fig.…”

Section: Data Collection By Means Of Photometrymentioning

confidence: 99%

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An autoradiographic method for determining nutrient competition between leaf epiphytes and plant pathogens

Edwards

Blakeman

1984

Journal of Microscopy

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SUMMARY A method is described for the study of nutrient competition between leaf surface microorganisms and plant pathogenic fungi. Autoradiography was used to investigate the uptake of water‐soluble 14C‐labelled nutrients by applying a dry pre‐formed layer of emulsion to the specimen. The method was adapted for use on both leaf and artificial surfaces. A photometric method was used for rapid examination of autoradiographs.

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Section: On Artificial Surfacesmentioning

confidence: 99%

Section: On Artificial Surfacesmentioning

confidence: 99%

Section: Data Collection By Means Of Photometrymentioning

confidence: 99%

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An autoradiographic method for determining nutrient competition between leaf epiphytes and plant pathogens

Edwards

Blakeman

1984

Journal of Microscopy

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“…The excitation spectrum, x ; the emission spectrum, 0 . 435.0 nm. The amount of light reflected from single silver grains is predictable (Neely & Combs, 1976), and this is a reliable method for grain counting (Rogers, 1972). The acriflavin fluorescence was measured at 590 nm.…”

Section: Specimen Measurementsmentioning

confidence: 99%

A computerized microspectrophotometer using fibre optics for transmission and detection of light

Neely

Townend

Combs

1984

Journal of Microscopy

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SUMMARY A computerized microspectrophotometer was developed to provide rapid and accurate sequential measurements on cells, including nuclear DNA content, by fluorescence staining, photometric grain counting from autoradiographs, and nuclear size estimated by measurement aperture area. To alleviate bulk and vibrations caused by additional stepper motors, the excitation light and filters as well as the emission filters and photomultipliers were detached from the main microscope frame. The light was directed to and from the microscope through fibre optic bundles. This configuration provided an excellent light gathering faculty and made optical alignment easier. The machine provided highly accurate sequential measurements on a relatively large number of cells by static photometry.

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“…The photometric method adopted for quantifying autoradiograms was based on the independent findings of Gullberg (11) and of Rogers (31,32) that silver grains, when illuminated from above, reflect light in proportion to their number in a given area. The microscope used was a Leitz Ortholux MPV1.…”

Section: Photometry Of Autoradiogramsmentioning

confidence: 99%

Secretory kinetics in the follicular cells of silkmoths during eggshell formation.

Blau¹,

Kafatos²

1978

The Journal of Cell Biology

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ABSTRAGTProcedures for quantitative autoradiography were used for studying the process of secretion of eggshell (chorion) proteins in the follicular epithelium of silkmoths. The method was based on photometric measurements of the reflectance of vertically illuminated autoradiographic silver grains. Results were analyzed and plotted by computer. Secretory kinetics were also determined by analysis of labeled proteins in physically separated epithelium and chorion. Rapid accumulation of radioactivity into "clumps" visualized by light microscope autoradiography and evidence from preliminary electron microscope autoradiography indicate that, within 2 min from the time of synthesis, labeled chorion proteins move to Golgi regions scattered throughout the cytoplasm. The proteins begin to accumulate in the apical area 10-20 rain later and to be discharged from the cell. The time for half-secretion is 20-25 min, and discharge is essentially complete 30-50 min after labeling. At the developmental stages examined, the kinetics of secretion appear to be similar for all proteins. Within the chorion the proteins rapidly assume a characteristic distribution, which varies for different developmental stages. Two relatively slow steps have been identified in secretion, associated with residence in Golgi regions and in the cell apex, respectively. By contrast, translocation of proteins across the cell and deposition of discharged proteins in the chorion are rapid steps.KEY WORDS secretion 9 quantitative autoradiography intracellular transport kinetics 9 photometry 9Kinetic studies of the secretory pathway have been limited by the methods commonly used, subcellular fractionation and electron microscopic autoradiography. These methods are well suited for identifying the organelles involved but are somewhat cumbersome for detailed kinetic studies. In the present paper, we describe widely applicable methods for quantitative light microscopic autoradiography. These methods have expedited the quantitative analysis of large numbers of autoradiograms, making possible detailed studies of secretory kinetics in the follicular epithelium of silkmoths. Studies using separation of cells from extracellular secreted products, plus preliminary electron microscope autoradiography, corroborated and extended the results of light microscope autoradiography. The major steps involved in secretion were identified and the duration of each step was evaluated. The follicular epithelium is well suited for studying secretory kinetics. It forms a monolayer around each oocyte and during the terminal pe-J. CELL BIOLOGY 9 The Rockefeller University Press -0021-9525/78/0701-013151.00 131

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Photometrie measurements of grain density in autoradiographs

Cited by 31 publications

References 7 publications

An autoradiographic method for determining nutrient competition between leaf epiphytes and plant pathogens

An autoradiographic method for determining nutrient competition between leaf epiphytes and plant pathogens

A computerized microspectrophotometer using fibre optics for transmission and detection of light

Secretory kinetics in the follicular cells of silkmoths during eggshell formation.

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