Array comparative genomic hybridization

Question 1

In this technique, a subject’s test DNA is labelled with a green fluorescent dye and mixed with reference genomic DNA labelled in red. The mixture is then hybridized to a microarray of 3, 000 genomic DNA sequences. Finally, the fluorescence is measured at each spot, with the green:red ratio indicating the relative abundance of subject versus reference DNA.

Answer 1

high-resolution aCGH

Question 1

Submicroscopic deletions and duplications located anywhere in the genome can be detected using ____.

Answer 1

high-resolution aCGH

Question 2

____ is based on sequence and marker data from the Human Genome Project. It utilises microarrays of thousands of DNA sequences, spaced at intervals along the chromosomes, spotted onto slides

Answer 2

Array CGH

Question 3

T/F. Arrays vary in resolution, from 1 Mb between sequences, to tiling path arrays with a resolution of about 1kb.

Answer 3

True

Question 4

In this technique, the ratios from all the spots can be plotted against a chromosome map to reveal regions of copy-number variation. The method identifies pathological duplications and deletions, which may be difficult to distinguish from non-pathological copy-number variation without parental samples or reference to population control data.

Answer 4

Array CGH

Question 4

T/F. Regions of deletion or duplication detected by a CGH can, if appropriate, be confirmed by FISH.

Answer 4

True.

Question 5

T/F. aCGH is increasingly being used to identify pathogenic regions of copy-number alteration in patients with unexplained learning disability and dysmorphic features. It can also be used to detect such alterations at chromo- some breakpoints in patients with apparently balanced reciprocal chromosome translocations.

Answer 5

True.