DNA Test Methods - DNA Microarrays

View the full Interactive Tutorial at:
http://www.phgfoundation.org/tutorials/dna/6.html

A DNA "chip" or microarray is prepared on a small solid base such as a piece of glass or nylon divided into a grid of tiny squares. To each square is attached a different and specific piece of DNA, typically a short DNA sequence that can act as a probe for a particular gene. DNA corresponding to thousands of different genes can be accommodated on a single array no bigger than a microscope slide.

A single stranded DNA sample of interest is cut up and then washed over the chip. Any sequence in the sample that matches a sequence on the chip will hybridise to it and, if the sample is suitably labeled (usually with a fluorescent tag) the pattern of matches can be visualised and analysed by computer, giving a read-out of the presence or expression level of hundreds of different sequences simultaneously.

DNA chips have many potential applications in biology and medicine. For example, they can be used to look for mutations in a gene, to measure how active a set of genes is in a particular cell or tissue type, to analyse how gene activity changes over time, or to compare the genotypes or gene expression profiles of different samples, for example the genotypes of people who do or do not respond to a particular drug, or the gene expression patterns of tumours compared to normal tissue.

Category:

Science & Technology

Tags:

• phgfoundation
• interactive
• tutorials
• dna
• test
• methods

[magiccatalyst]

bravo. i agree this is the best explained microarray vid on youtube.

[Illimitus]

straight and to the point

[iLOVENATURE2011]

excellent video...

[laliciacourt]

hey all guys out there, who knows how microbial virulence factors are identified using microarrays? which type of micro array is used for this?

[dnanalahcnap]

simple, confident, and informative. More than I can say about my teacher.

[jessetsilva]

Awesome explanation!

[deknoifd]

thanks for produce excellent video for my study ;)

[darbs264]

excellent video, thanks

[audassity1]

great video

[MissMoonwalkBaby]

Brilliant, thank you :)

[Supratrochlearis]

Are these probes, attached to the squares, simply any DNA elemet (might be a sequence of some gene), known to hybridize with a specific cDNA or RNA element?

I reckon it's not from the very gene that interest us - it's expression and such.