Question: What are GMOs used for?
About the article "DNA", section "Genetic engineering".

Candidate passages:
The construct-specific detection methods can either be DNA or protein based.
DNA based detection looks for a part of the foreign DNA inserted in a GMO.
For technical reasons, certain DNA sequences are shared by several GMOs.
Protein-based methods detect the product of the transgene, for example the Bt toxin.
Since different GMOs may produce the same protein, construct-specific detection can test a sample for several GMOs in one step, but is unable to tell precisely which of the similar GMOs are present.
Especially in the USA, protein-based detection is used for the construct-specific approach. 
Almost all transgenic plants contain a few common building blocks that make unknown GMOs easier to find.
Even though detecting a novel gene in a GMO can be like finding a needle in a haystack, the fact that the needles are usually similar makes it much easier.
To trigger gene expression, scientists couple the gene they want to add with what is known as a transcription promoter.
The high-performing 35S promoter is a common feature to many GMOs.
In addition, the stop signal for gene transcription in most GMOs is often the same: the NOS terminator.
Researchers now compile a set of genetic sequences characteristic of GMOs.
After genetic elements characteristic of GMOs are selected, methods and tools are developed for detecting them in test samples.
Approaches being considered include microarrays and anchor PCR profiling. 
A genetically modified organism (GMO) is an organism whose genetic material has been altered using genetic engineering techniques.
Organisms that have been genetically modified include micro-organisms such as bacteria and yeast, insects, plants, fish, and mammals.
GMOs are the source of genetically modified foods, and are also widely used in scientific research and to produce goods other than food.
The term GMO is very close to the technical legal term, 'living modified organism' defined in the Cartagena Protocol on Biosafety, which regulates international trade in living GMOs (specifically, "any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology").
This article focuses on what organisms have been genetically engineered, and for what purposes.
The article on genetic engineering focuses on the history and methods of genetic engineering, and on applications of genetic engineering and of GMOs.
Both articles cover much of the same ground but with different organizations (sorted by organism in this article; sorted by application in the other).
There are separate articles on genetically modified crops, genetically modified food, regulation of the release of genetic modified organisms, and controversies. 
Once characterized and manipulated to provide signals for appropriate expression, cloned genes may be inserted into organisms, generating transgenic organisms, also termed genetically modified organisms (GMOs).
Although most GMOs are generated for purposes of basic biological research (see for example, transgenic mouse), a number of GMOs have been developed for commercial use, ranging from animals and plants that produce pharmaceuticals or other compounds (pharming), herbicide-resistant crop plants, and fluorescent tropical fish (GloFish) for home entertainment. 
There are numerous applications for quantitative polymerase chain reaction in the laboratory.
It is commonly used for both diagnostic and basic research.
Uses of the technique in industry include the quantification of microbial load in foods or on vegetable matter, the detection of GMOs (Genetically modified organisms) and the quantification and genotyping of human viral pathogens.