Analyses of brain tumor cell lines confirm a simple model of relationships among fluorescence in situ hybridization, DNA index, and comparative genomic hybridization

✍ Scribed by Gayatry Mohapatra; Dan H. Moore; Dong H. Kim; Lovedeep Grewal; William C. Hyun; Frederic M. Waldman; Daniel Pinkel; Burt G. Feuerstein

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 134 KB
• Volume: 20
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/(sici)1098-2264(199712)20:4<311::aid-gcc1>3.0.co;2-4

✦ Synopsis

Several techniques are commonly used for genetic analysis of interphase nuclei. Flow cytometry assays the distribution of DNA content in populations of nuclei stained with a DNA-specific fluorochrome. Fluorescence in situ hybridization (FISH) quantifies the number of copies of a specific DNA sequence in single nuclei. Comparative genomic hybridization (CGH) assesses the relative copy number of DNA sequences throughout a test genome by comparing the signal intensities of test and reference DNA samples hybridized to a template of normal metaphase chromosomes. In principle, there are specific relationships among data obtained from these measurements, and combined measurements should provide a more comprehensive view of the sample that is analyzed. We applied these three techniques to nine brain tumor cell lines and find that a model of CGH that includes unsuppressed repeat sequences describes the data well. We estimate that up to 35% of the fluorescence intensity in well-blocked CGH preparations may not represent unique sequences. Taking these factors into account, our results are, in general, mutually consistent, and highlight issues critical for interpreting CGH preparations.