Comparative Genomic Hybridization Using Oligonucleotide Microarrays and Total Genomic DNA

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 101; no. 51; pp. 17765 - 17770
• Main Authors: Barrett, Michael T., Scheffer, Alicia, Ben-Dor, Amir, Sampas, Nick, Lipson, Doron, Kincaid, Robert, Tsang, Peter, Curry, Bo, Baird, Kristin, Meltzer, Paul S., Yakhini, Zohar, Bruhn, Laurakay, Laderman, Stephen, Caruthers, Marvin H.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 21.12.2004; National Acad Sciences
• Subjects: Biological Sciences; Cancer; Cell Line; Cell lines; Chromosome Aberrations; Chromosomes; Comparative genomic hybridization; Datasets; Deoxyribonucleic acid; DNA; DNA - genetics; DNA probes; Female; Gene Deletion; Gene Expression Profiling; Genetics; Genome; Genomes; Genomics; Homozygote; Humans; Male; Nucleic Acid Hybridization - methods; Oligonucleotide Array Sequence Analysis - methods; Oligonucleotide probes; Oligonucleotides; Research Design; Sensitivity and Specificity
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0407979101

Array-based comparative genomic hybridization (CGH) measures copy-number variations at multiple loci simultaneously, providing an important tool for studying cancer and developmental disorders and for developing diagnostic and therapeutic targets. Arrays for CGH based on PCR products representing assemblies of BAC or cDNA clones typically require maintenance, propagation, replication, and verification of large clone sets. Furthermore, it is difficult to control the specificity of the hybridization to the complex sequences that are present in each feature of such arrays. To develop a more robust and flexible platform, we created probedesign methods and assay protocols that make oligonucleotide microarrays synthesized in situ by inkjet technology compatible with array-based comparative genomic hybridization applications employing samples of total genomic DNA. Hybridization of a series of cell lines with variable numbers of X chromosomes to arrays designed for CGH measurements gave median ratios for X-chromosome probes within 6% of the theoretical values (0.5 for XY/XX, 1.0 for XX/XX, 1.4 for XXX/XX, 2.1 for XXXX/XX, and 2.6 for XXXXX/XX). Furthermore, these arrays detected and mapped regions of single-copy losses, homozygous deletions, and amplicons of various sizes in different model systems, including diploid cells with a chromosomal breakpoint that has been mapped and sequenced to a precise nucleotide and tumor cell lines with highly variable regions of gains and losses. Our results demonstrate that oligonucleotide arrays designed for CGH provide a robust and precise platform for detecting chromosomal alterations throughout a genome with high sensitivity even when using full-complexity genomic samples.