Array Comparative Genomic Hybridization: A Powerful Advance in Molecular Cytogenetics

Introduction

Array comparative genomic hybridization (CGH) is a molecular cytogenetic technique that uses two genomes—a test and a control—which are differentially labeled and competitively hybridized to an array of DNA probes. This allows for the detection of copy number changes, such as deletions or duplications, across the entire genome.

History and Development

CGH was first developed in the early 1990s to detect copy number changes in solid tumors. It has since been adapted for use in a wide range of applications, including the detection of chromosomal abnormalities in prenatal diagnosis, the identification of genomic rearrangements in cancer cells, and the study of genetic variation in populations.

Methodology

Array CGH is performed by extracting DNA from the test and control samples and labeling the DNA with different fluorescent dyes. The labeled DNA is then hybridized to an array of DNA probes, which are complementary to specific regions of the genome. The hybridization signal is detected and quantified, and the data is analyzed to identify copy number changes.

Applications

Array CGH has a wide range of applications in clinical and research settings, including:

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• Detection of chromosomal abnormalities in prenatal diagnosis
• Identification of genomic rearrangements in cancer cells
• Study of genetic variation in populations
• Identification of candidate genes for genetic diseases

Array CGH is a powerful tool that has revolutionized the field of cytogenetics. It has enabled the detection of a wide range of genetic abnormalities that were previously difficult or impossible to detect.