Article No. |
Title |
CLC1001 |
Evaluation of an Automated Colony Counter |
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W. A. GOSS , R. N. MICHAUD, AND M. B. McGRATH |
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An automated colony counter was found to readily detect surface and subsurface bacterial colonies
of 0.3 mm size or greater with a high degree of precision. On a logarithmic scale, counting efficiency consistently
ranged from 89 to 95% of corresponding manual count determinations for plates containing up to 1,000 colonies.
In routine application, however, automated plate counts up to approximately 400 colonies were selected as a
more practical range for operation. The automated counter was easily interfaced with an automated data acquisition
system. |
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CLC1002 |
The Use of Adult Rat Liver Cultures in the Detection of the Genotoxicity of Various Polycyclic Aromatic Hydrocarbons |
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C. TONG, M. F. LASPIA, S. TELANG, AND G. M. WILLIAMS |
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The hepatocyte primary culture (HPC)-DNA repair test and the adult rat liver epithelial cell
(ARL)-hypoxanthine-guanine phosphoribosyl transferase (HGPRT) mutagenesis assay are two in vitro short-term
tests that possess intrinsic capability for xenobiotic biotransformation. Both assays detected the genotoxicity
of a variety of carcinogenic polycyclic aromatic hydrocarbons. Thus, these two tests, which embody intact cellular
metabolism, are useful for the evaluation of this class of carcinogens and provide results that strengthen those
obtained in tests dependent upon subcellular metabolism. |
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CLC1003 |
Health Effects Of Chemicals: V. Computer-Assisted Genetic Toxicology Testing |
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LEON S. OTIS, ROSIE Mc CORMICK, AND BETTY STROMNESS |
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Until recently manual grain counting took hours for each slide and made routine testing with
this procedure impractical. With the new automated system, grains are counted using a "colony counter,"
which can detect the exposed silver grains using a contrast-discriminator. Grain counting, therefore, can be accomplished in the
time it takes to focus the microscope on a cell, set an electronic aperture over the desired counting region
(which is displayed on a TV monitor), and push a count button on the colony counter. The data are fed directly
into a file in the computer, eliminating the need to record raw data manually. This system has reduced the
time required to score 50 cells per slide from a few hours to an average of less than 10 minutes. In addition,
all subsequent processing of data is accomplished by computer programs with no additional entry of data required. |
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 |
CLC1004 |
A Rapid, Semi-Automated Counting Procedure for Enumeration of Antibody-Forming Cells in Gell and Nucleated Cells
in Suspension |
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DAVID H. KATZ, MERYL FAULKNER, LEE R. KATZ, ERIK LINDH, CHARLES C. LEONHARDT,
KIMBERLEY HERR AND AMAR S. TUNG |

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Since the description by Jerne et al (1) of the hemolysis-in-gel technique for enumerating
single antibody-producing cells, this procedure has become one of standard usage in most laboratories engaged
in immunological research. Different laboratories use a variety of modifications of the technique, whether
in a gel support medium as initially described or the suspension technique described by Cunningham and Szenberg
(2). Irrespective of the modification employed, the final analysis involves enumeration of plaques which
have developed in the indicator erythrocyte suspension. Typically, this has been done visually by examining
either slides or petri dishes with an appropriate light source either with or without the aid of a suitable
magnifying lens or stereozoom microscope. |
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 |
CLC1005 |
Purification and Properties of a Rat Liver Protein that Specifically Inhibits the Proliferation of Nonmalignant
Epithelial Cells from Rat Liver |
|
JAMES B. McMAHON, JAMES G. FARRELLY, AND P. THOMAS IYPE |

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In inhibitor of cell proliferation was purified from rat liver by alcohol precipitation, ultrafiltration,
and DFAE-cellulose chromatography. The hepatic proliferation inhibitor was shown to be pure by polyacrylamide gel
electrophoresis in the presence of sodium dodecyl sulfate, analytical isoelectric focusing, and high-performance
liquid chromatography. The hepatic proliferation inhibitor was found to have a'molecular weight of 26,000 and an
isoelectric point of 4.65. This protein inhibited the proliferation of nonmalignant rat liver cells in culture,
and removal of the protein reversed the inhibition produced by low doses. It exerted no effect on the proliferation
of malignant rat liver cells. |
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CLC1006 |
Semi-Automated Grain and Cell Counting |
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PAUL A. BRUNN JR., SHARON S. FORD, STANLEY E. SHACKNEY |

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A commercially available bacterial colony counter has been adapted for the counting
of radioautographic grains over individual cells in smears, and for counting cells in histologic sections.
For the counting of radioautographic grains, the correlation coefficients between counts obtained visually by two
observers, and between counts obtained visually and using the instrument were similar (r = .999 and r =
.998 respectively). The instrument counts were obtained more rapidly than the visual counts and were associated
with less observer fatigue. While performance of the instrument in counting cells in mouse bone marrow sections
was less accurate than in counting radioautographic grains, a good estimation of marrow cell number was
obtained (r = .968). Data on bone marrow cellularity was obtained far more rapidly than with semi-quantitative
methods. |
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 |
CLC1007 |
Semi-Automated Autoradiographic Measurement of DNA Repair In Normal and Xeroderma Pigmentosum Cultured
Human Fibroblasts |
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KENNETH H. KRAEMER, JOSEPH K. BUCHANAN, AND SHERMAN F. STINSON |

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Assessment of DNA repair in cultured human fibroblasts by autoradiography may be facilitated
by using semi-automated grain counting instruments. The instrument determined number of autoradiographic
grains per nucleus in cultured human skin fibroblasts was found to be linear in comparison to visual counts
up to only 30 grains per nucleus. However, with two different instruments a greater range of linearity (100
to 120 grains per nucleus) was attained by measuring the grain surface area per nucleus. Semi-automated analysis
of the grain surface area per nucleus yielded measurements of relative rates of unscheduled DNA synthesis after
ultraviolet irradiation in xeroderma pigmentosum and normal human fibroblasts, which were reproducible and
rapid. |
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CLC1008 |
From Image to Analysis: Object Detection and Measurement |
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MICHAEL K. BENDER |

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Image Analyzers, both manual and automated, allow users to identify objects and to categorize I them using various geometric parameters. Densitometric identification and categorization is also possible with some image analysis equipment. Although image analyzers are not a recent development, many of their applications are new. Technological developments in the last decade
have extended the capabilities of image analyzers by increasing speed, accuracy, and flexibility. The instruments
have also become significantly more affordable. |
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 |
CLC1009 |
Detection, Enumeration, and Sizing of Planktonic Bacteria by Image-Analyzed Epifluorescence Microscopy |
|
MICHAEL E. SIERACKI, PAUL W. JOHNSON, AND JOHN McN. SIEBURTH |

|
Epifluorescence microscopy is now being widely used to characterize planktonic
procaryote populations. The tedium and subjectivity of visual enumeration and sizing have been largely alleviated
by our use of an image analysis system consisting of a modified Artek 810 image analyzer and an Olympus BHT-F
epifluorescence microscope. This system digitizes the video image of autofluorescing or fluorochrome-stained
cells in a microscope field. The digitized image can then be stored, edited, and analyzed for total count
or individual cell size and shape parameters. Results can be printed as raw data, statistical summaries, or
histograms. By using a stain concentration of 5 mg of 4'6-diamidino -2-phenylindole per ml of sample and
the optimal sensitivity level and mode, counts by image analysis of natural bacterial populations from a variety
of habitats were found to be statistically equal to standard visual counts. Although the time required to
prepare slides, focus, and change fields is the same for visual and image analysis methods, the time and
effort required for counting is eliminated since image analysis is instantaneous. The system has been satisfactorily
tested at sea. Histograms of cell silhouette areas indicate that rapid and accurate estimates of bacterial biovolume
and biomass will be possible with this system. |
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CLC1010 |
Automated Radiographic Grain Counting: Correction for Grain Overlap |
|
W.H. SCHUETTE, S.S. CHEN, S.J. OCCHIPINTI, H.S. MUJAGIC, AND S.E. SHACKNEY |
 |
An algorithm is described for the calculation of radioautographic cell grain count from measurements
of total cell nuclear area and total grain area. This algorithm provide-s a statistical correction for grain
overlap that is based on the solution to the occupancy problem in probability theory. This method permits the
use of automated grain counting over a wide range of grain counts/cell, and extends the useful dynamic range
of radioautographic grain counting to well over 200 grains/cell. |
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