Comparative Genomic Hybridization
Comparative Genomic Hybridization - Related Videos
09:16
Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
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Cited by 7 •
2015
Array CGH for the detection of genomic copy number variants has replaced G-banded karyotype analysis. This paper describes the technology and its application in a diagnostic service laboratory.
16:37
Technical Demonstration of Whole Genome Array Comparative Genomic Hybridization
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Cited by 5 •
2008
This video is a technical demonstration of the hybridization protocol for whole genome tiling path array CGH, which scans the entire human genome using only 25-100 ng of DNA that can be isolated from a variety of sources, including archival formalin fixed material.
02:16
Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes
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2020
The present-day mitochondrial and chloroplast genomes have retained some of the characteristics of their ancestral prokaryotes and also have acquired new attributes during their evolution within eukaryotic cells. Like prokaryotic genomes, mitochondrial and chloroplast genomes neither bind with histone-like proteins nor show complex packaging into chromosome-like structures, as observed in eukaryotes. Unlike mitotic cell divisions observed in eukaryotic cells, mitochondria and chloroplasts...
12:08
Hybrid De Novo Genome Assembly for the Generation of Complete Genomes of Urinary Bacteria using Short- and Long-read Sequencing Technologies
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Cited by 9 •
2021
This protocol details a comprehensive approach for the culturing, sequencing, and de novo hybrid genome assembly of urinary bacteria. It provides a reproducible procedure for the generation of complete, circular genome sequences useful in studying both chromosomal and extrachromosomal genetic elements contributing to urinary colonization, pathogenesis, and antimicrobial resistance dissemination.
16:42
Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides
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Cited by 4 •
2010
This work shows how to form an RNA/DNA hybrid at the chromosomal level and reveal transfer of genetic information from RNA to genomic DNA in yeast cells.
FAQs
The key measurement is the relative fluorescence produced by patient and reference DNA after they hybridize to the same genomic targets. When the patient sample contains more or less DNA from a region than the reference, the fluorescence balance shifts at that location. Researchers use these regional differences to identify genomic gains, losses, or amplifications.
Chromosome-based CGH evaluates fluorescence differences across normal chromosomes, whereas array-based CGH measures hybridization across DNA features distributed on a microarray. This array format supports more detailed examination of genomic regions and can reveal submicroscopic deletions and duplications that chromosome-based analysis may not resolve. The choice therefore affects the scale of detectable abnormalities.
Reference DNA provides the comparison needed to interpret the patient sample's genomic representation. Both labeled samples are mixed before hybridization, so fluorescence differences reflect unequal representation between them rather than an isolated signal from the patient alone. This comparative design allows gains, losses, and amplifications to be located across the genome.
A typical workflow begins with patient and reference DNA, followed by fluorescent labeling of the two samples. The labeled material is mixed and hybridized either to normal chromosomes or to a DNA microarray. Researchers then examine regional fluorescence differences to identify genomic areas where the patient and reference samples are not equally represented.
CGH is useful when investigators need to characterize chromosomal abnormalities associated with genetic disease. Its applications include evaluating developmental disorders, unexplained congenital conditions, and genomic changes linked to cancer. By showing where copy-number differences occur, the technique supports both diagnostic investigation and further characterization of the underlying chromosomal abnormality.
The method can identify genomic gains, losses, and amplifications, including submicroscopic deletions and duplications when an array is used. These findings help describe chromosomal abnormalities at a level relevant to genetic disease, cancer-associated genomic changes, developmental disorders, and congenital conditions. The resulting copy-number profile provides information for diagnosis and genomic characterization.