logo
    Molecular cytogenetic characterization of drug-resistant leukemia cell lines by comparative genomic hybridization and fluorescence in situ hybridization
    0
    Citation
    0
    Reference
    20
    Related Paper
    The quality of cytogenetic analysis of solid tumours has greatly improved in the past decade, but a number of technical difficulties remain which limit the characterization of solid tumour chromosomes by conventional cytogenetics alone. The identification of regions of chromosomal abnormality has been aided by the introduction of molecular cytogenetic techniques such as fluorescence in situ hybridization (FISH). Of these, a recently developed approach, comparative genomic hybridization (CGH), has had a particular impact on the cytogenetic analysis of solid tumours. It incorporates the sensitivity of in situ techniques and overcomes many of the drawbacks of conventional cytogenetic analysis. This review first outlines the CGH method, giving details for the preparation of DNA probes and target human metaphase chromosomes together with information on the in situ technique and data handling criteria used in our laboratory. It then presents an overview of some of the current applications of CGH, together with a discussion of future directions in the field. Copyright © 1999 John Wiley & Sons, Ltd.
    Comparative genomic hybridization
    Molecular cytogenetics
    Molecular cytogenetics
    Characterization
    Comparative genomic hybridization
    Comparative genomic hybridization (CGH) has been established as an informative technique in genetic analysis. However, differences in the ratio of hybridization intensities were reported for particular chromosomes, which may affect CGH results. The aim of this study was to define these differences in more detail. For this purpose, CGH results of 70 samples of bone marrow cells (BMC) with normal karyotype in conventional cytogenetics (CC) were evaluated using seven different reference DNAs and two different DNA labeling systems.CGH using fluorochrome-conjugated nucleotides for DNA labeling indicated signal deviations in 21/70 BMC samples. Deviations affected chromosomes 1 (n = 21), 2 (n = 11), 4 (n = 11), 5 (n = 9), 6 (n = 7), 7 (n = 2), 8 (n = 2), 12 (n = 5), 13 (n = 15), 14 (n = 1), 16 (n = 17), 17 (n = 11), 19 (n = 21), 20 (n = 12), and/or 22 (n = 17). None of the imbalances were confirmed by fluorescence in situ hybridization (FISH). Using digoxigenin and biotin-conjugated nucleotides in exemplary cases (n = 5) led to the disappearance of the signal deviations. Repeated CGH experiments using seven different reference DNAs showed remarkable variations in the signal deviations.Hybridization differences depend not only on the hapten or fluorochrome-labeled nucleotides used for DNA labeling, but also on the reference DNA chosen. Therefore, close control of CGH experiments is mandatory, and additional techniques such as FISH should be performed to confirm the results obtained by CGH.
    Comparative genomic hybridization
    Hybridization probe
    Digoxigenin
    Citations (2)