arrayCGHskaalamikroelementtejä

Array comparative genomic hybridization (arrayCGH) is a molecular cytogenetic technique used to detect genomic imbalances in DNA. It is a powerful tool for identifying copy number variations (CNVs) in the genome, which can be associated with various genetic disorders and diseases. The arrayCGH process involves the following steps:

1. DNA extraction: Genomic DNA is extracted from the sample, typically from blood or tissue.

2. Labeling: The extracted DNA is labeled with fluorescent dyes, such as Cy3 (green) and Cy5 (red), to create two separate samples.

3. Hybridization: The labeled DNA samples are hybridized to a high-density microarray, which contains millions of short DNA probes representing the entire genome.

4. Scanning: The microarray is scanned using a fluorescence microscope to detect the hybridized DNA.

5. Data analysis: The fluorescence intensity of each probe is measured, and the ratio of the two dyes is calculated. This ratio indicates the relative copy number of the corresponding genomic region.

ArrayCGH can detect both gains and losses of DNA, with a resolution of approximately 100 kb to 1 Mb, depending on the microarray platform used. It is widely used in clinical genetics, cancer research, and evolutionary biology to study genomic imbalances and their impact on phenotype. ArrayCGH has several advantages over traditional CGH, including higher resolution, increased throughput, and the ability to analyze multiple samples simultaneously. However, it also has some limitations, such as the need for high-quality DNA and the potential for false positives due to technical artifacts.