High-resolution scanning-densitometry of photographic negatives of human metaphase chromosomes

1974 ◽  
Vol 42 (1) ◽  
pp. 9-29 ◽  
Author(s):  
M. van der Ploeg ◽  
P. van Duijn ◽  
J. S. Ploem
1974 ◽  
Vol 42 (1) ◽  
pp. 31-46 ◽  
Author(s):  
M. van der Ploeg ◽  
P. van Duijn ◽  
J. S. Ploem

1977 ◽  
Vol 51 (4) ◽  
pp. 269-291 ◽  
Author(s):  
M. van der Ploeg ◽  
A. M. Vossepoel ◽  
F. Th. Bosman ◽  
P. van Duijn

Author(s):  
B. A. Hamkalo ◽  
Elizabeth R. Unger

This symposium brings together several approaches for the detection of specific nucleic acid sequences that have potential applications at the histochemical level.Trask et al. report on the use of fluorescence in situ hybridization (FISH) techniques to study the arrangement of DNA sequences in normal and diseaserelated chromosomes. The sites of specific DNA sequences can be fluorescently tagged. Different sequences can be labeled with different fluorochromes so that their arrangement can be studied using fluorescence microscopy. The distances between points on the same or different chromosomes can be determined in a large number of interphase nuclei or metaphase chromosomes. A variety of probe types, ranging from single-copy sequences to highly repeated sequences can be employed.Hamkalo and co-workers have used non-radioactive methods at the EM level for the detection of nucleic acid sequences by in situ hybridization. Analysis of metaphase chromosomes by electron microscopy allows for high resolution mapping of chromosomes. A variety of labelling procedures have been employed to illustrate the utility of high resolution nucleic acid sequence mapping in these preparations.


1974 ◽  
Vol 22 (7) ◽  
pp. 478-491 ◽  
Author(s):  
SAMUEL A. LATT

Fluorescence of the dye 33258 Hoechst, when bound to chromosomes, is partially quenched by the incorporation of 5-bromodeoxyuridine into chromosomal deoxyribonucleic acid (DNA). This effect allows microfluorometric analysis of DNA synthesis. Metaphase chromosomes from cultured human leukocytes which have incorporated 5-bromodeoxyuridine for a portion of the DNA synthesis period exhibit reduced 33258 Hoechst fluorescence in 5-bromodeoxyuridine-containing regions. Regions synthesizing DNA during a particular interval can thus be highlighted by the appropriate protocol of 5-bromodeoxyuridine administration. Chromosomes from cells which have replicated twice in medium containing 5-bromodeoxyuridine exhibit one brightly and one dully fluorescing chromatid, reflecting incorporation of 5-bromodeoxyuridine into one or two chains of chromatid DNA, respectively. Sister chromatid exchanges, evident as sharply demarcated reciprocal alterations in fluorescence along chromosomes, can be located relative to quinacrine banding patterns. This fluorometric approach should be useful in many instances as a convenient, high resolution alternative to autoradiography.


Chromosoma ◽  
1994 ◽  
Vol 103 (6) ◽  
pp. 393-400 ◽  
Author(s):  
R. Rizzoli ◽  
E. Rizzi ◽  
M. Falconi ◽  
A. Galanzi ◽  
B. Baratta ◽  
...  

2003 ◽  
pp. 245-254
Author(s):  
Stefan Thalhammer ◽  
Pietro Gobbi ◽  
Mirella Falconi ◽  
Giovanni Mazzotti ◽  
Wolfgang M. Heckl

Chromosoma ◽  
1994 ◽  
Vol 103 (6) ◽  
pp. 393-400 ◽  
Author(s):  
R. Rizzoli ◽  
E. Rizzi ◽  
M. Falconi ◽  
A. Galanzi ◽  
B. Baratta ◽  
...  

1982 ◽  
Vol 56 (1) ◽  
pp. 409-422 ◽  
Author(s):  
C.J. Harrison ◽  
T.D. Allen ◽  
M. Britch ◽  
R. Harris

Human metaphase chromosomes, prepared for light microscopy were examined by scanning electron microscopy. Use of an osmium impregnation technique eliminated the need for sputter-coating and allowed high-resolution visualization of uncoated specimens. Chromosomes were of three-dimensional cylindrical profile, with well-defined chromatids and centromeres. Prior to Giemsa-banding a smooth surface morphology was observed. Relaxation of chromosome integrity by Giemsa-banding pretreatment allowed resolution of several orders of chromosome structure not previously demonstrated by scanning electron microscopy. The observed organization of the chromatin fibres allowed parallels to be drawn with the radial loop model of chromosome construction as described by Marsden and Laemmli.


Author(s):  
Riccardo Levi-Setti ◽  
Jan M. Chabala ◽  
Konstantin Gavrilov ◽  
Rafael Espinosa ◽  
Michelle M. Le Beau

Author(s):  
William H. Escovitz ◽  
Timothy R. Fox ◽  
Riccardo Levi-Setti

Radiation damage of biological specimens has become a great concern of scientists in high resolution microscopy. Although modern refinements have pushed the ultimate resolution of microscopes below 5Å, specimen damage and preparation techniques have thwarted the realization of this resolution in biological molecules near their natural states. Because Scanning Transmission Ion Microscopy (STIM) with protons is thought to be much more damaging than electron microscopy, critics have doubted the applicability of proton microscopy to biological research, especially at high resolution. As a first step in exploring proton-beam induced damage in biological material, whole-mount chromosomes have been imaged at low resolution by proton microscopy for the first time. After prolonged proton irradiation, the same chromosomes were examined by Conventional Transmission Electron Microscopy (CTEM).Figure 1 is a bright-field proton micrograph of a chromosome obtained from human peripheral lymphocytes. The specimen, prepared by Dr. H. M. Golomb, is unstained and critical-point dried.


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