| has gloss | eng: In biology, a branched DNA assay is a test for specific nucleic acid chains, and is typically used to detect retroviruses such as HIV. However, the assay can be used to detect and quantitate other types of RNA or DNA target. In the assay, branched DNA is mixed with a sample to be tested. The detection is done using a non-radioactive method and does not require preamplification of the nucleic acid to be detected. The assay entirely relies on hybridization. Enzymes are used to indicate the extent of hybridization but are not used to manipulate the nucleic acids. Thus, small amounts of a nucleic acid can be detected and quantified without a reverse transcription step (in the case of RNA) and/or PCR. The assay can be run as a "high throughput assay", unlike quantitative Northern-blotting or the RNAse-protection assay, which are labor-intensive and thus difficult to perform on a large number of samples. The other major high throughput technique employed in the quantitation of specific RNA molecules is quantitative PCR, after reverse transcription of the RNA to cDNA. |