I am afraid is quite an in-depth subject.
in layman's terms, if you imagine a glass slide with lots of very small dots (500,000 of them). these dots (probes) are complementary DNA, which has been stuck to the slide.
If you then take a sample of mRNA (expressed DNA) from the patient and turn it into DNA (cDNA). If you then put that cDNA on top of the dots on the slide and incubate, if that patients gene is being expressed it will bind to the probes stuck on the glass. This binding to the probe causes fluorescence, which can be detected.
If you compare the expression patterns between a healthly individual and a diseased individual you can try and work out what genes are being expressed differently in that condition (for research purposes). If you already know a certain gene is over expressed in a disease (e.g. BRAC2 in Breast cancer), you can then diagnose the patient.
Likewise you can use microarrays to predict what diseases you may develop in the future - for example you may be found to have a gene found in Alzheimer's for instance.
This is a very very brief introduction to the subject and its very interesting, you may like to try the following link if you'd like some more information on the subject.
http://plasticdog.cheme.columbia.edu/undergraduate_research/projects/sahil_mehta_project/work.htm
DNA microarray analysis is a technique used to match up two strands of DNA. It is used in paternity tests and in criminal investigations in which a perpetrator's DNA was found at the crime scene.
A cDNA microarray is a hybrid of a DNA microarray, which is a collection of a number of minute DNA dots. These are mostly used in the field of genetic testing.
mRNA is extracted from cells for DNA microarray. the mRNA is then converted in the lab to cDNA this cDNA is allowed to interact with the probes on the microarray chip
Otherwise known as "microarray chips," DNA microarray are used to determined the genetic makeup of a given tissue sample. By shining various bands of light on these chips, the gene(s) in the tissue are expressed in the form of a particular color.
no profit to answer
DNA Microarray
Advantages and disadvantages, microarrayAdvantages of DNA microarray tests include high throughput (lots of information with one test), and good coverage of the genome with the chips that have larger numbers of test spots. Disadvantages include incomplete coverage, which can lead to false normal results, and the ability to test only for unbalanced rearrangements (duplications and deletions), and not balanced translocations or inversions.However being high throughput and cost effective are the most elements for this technology, it still suffers lack of perfect processing methods and acceptable sensitivity as much as real time PCR
Step 1: Isolate the mRNA. Step 2: Make cDNA by reverse transcription using fluorescent labeled nucleotides. Step 3: Apply the cDNA mixture to a microarray with a different gene in each spot. Step 4: Rinse off excess DNA; scan for fluorescence.
DNA chip or also called as DNA microarray is a collection of microscopic DNA spot attached to a firm surface. This is used by scientist to measure the expression level of the large amount of genes or to genotype numerous regions of a genome.
There are three types of genealogical DNA tests, autosomal (atDNA), mitochondrial DNA. A list of single nucleotide polymorphisms (SNPs) is returned.
They both take a DNA sample
A microarray is a multiplex lab-on-a-chip. It is a 2D array on a solid substrate (usually a glass slide or silicon thin-film cell) that assays large amounts of biological material using high-throughput screening methods