07+Microarrays

Microarrays

Describe: Consists of tiny amounts of a large number of single-stranded DNA fragments representing different genes fixed to a glass slide in a grid or a tightly spaced array, it is also called a DNA chip (analogy to a computer chip), usually represent the genes in a human with the fragments

Analyze: A tissue sample is taken from an organism. The mRNA is isolated from the rest of the DNA. It is then paired with cDNA after going through reverse transcription. Fluorescently labeled nucleotides are added to the cDNA. The cDNA is then added to the microarray, which is a microscope slide on which copies of single-stranded DNA fragments from the organism’s genes are fixed. Each tray has spots for each separate gene. The cDNA hybridized with complementary DNA on the microarray, and then it is scanned for fluorescence. Each fluorescent spot represents an active gene, or a gene being expressed in the sample.

Apply:  Microarrays can be used to determine which genes are being expressed. If the genes are active, or being expressed, they get a fluorescent color added to them, as if they are being tagged. They can only be tagged if the cDNA is bound to a complementary DNA after going through reverse transcription. The genes are then separated and placed on separate spots on the tray and are tested to see if they are active.

Synthesize:  Microarrays are like computer chips. They both can take on a lot of information and can screen things. Computer chips can screen things by blocking viruses and any other bad things that can appear on a computer, even junk mail. Microarrays have the screenings to determine which genes are expressed.

 Argue:  I am for microarrays because it helps us figure out diseases better and help find new ways to treat the diseases. It also allows us to come up with new therapies and treatments. Information from the microarrays would provide a better view of how ensembles of genes interact to form a certain organism and to maintain its vital systems.

sources: AP Biology textbook, eighth edition



Microarray Animation