Array comparative genomic hybridization (array CGH) for detection of genomic copy number variants.
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 clinical diagnostic service laboratory. DNA extracted from a patient's sample (blood, saliva or other tissue types) is labeled with a fluorochrome (either cyanine 5 or cyanine 3). A reference DNA sample is labeled with the opposite fluorochrome. There follows a cleanup step to remove unincorporated nucleotides before the labeled DNAs are mixed and resuspended in a hybridization buffer and applied to an array comprising ~60,000 oligonucleotide probes from loci across the genome, with high probe density in clinically important areas. Following hybridization, the arrays are washed, then scanned and the resulting images are analyzed to measure the red and green fluorescence for each probe. Software is used to assess the quality of each probe measurement, calculate the ratio of red to green fluorescence and detect potential copy number variants.
Cytogenetics Department, Guy's & St Thomas' NHS Foundation Trust; joowook.ahn@nhs.net.
Joo Wook
JW
Ahn
Cytogenetics Department, Viapath Analytics.
Michael
M
Coldwell
Cytogenetics Department, Viapath Analytics.
Susan
S
Bint
Cytogenetics Department, Guy's & St Thomas' NHS Foundation Trust.
Caroline
C
Mackie Ogilvie
D055028:Comparative Genomic Hybridization / Q000379:methods*; D004247:DNA / Q000737:chemistry* / Q000235:genetics*; D056915:DNA Copy Number Variations; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D015894:Genome, Human; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D006801:Humans; D007621:Karyotyping / Q000379:methods
D015342:DNA Probes; D004247:DNA