Double stranded ribonucleic acid (RNA) is a unique form of RNA that appears with two complementary strands, instead of a single strand in isolation, as is more common for this genetic material. RNA contains the code for a number of biological activities and plays an important role in living organisms. Double stranded RNA, also known as dsRNA, usually shows up in viruses and is somewhat unusual. In viruses, it is a unique characteristic, and only a small number of viral families exhibit this trait.
RNA is formed of chains of nucleic acids that attach to each other to form a connected strand. Single stranded forms can have a very complex structure because they fold on each other and create elaborate three dimensional forms. Double stranded RNA can become even more complex, as the two chains of genetic material will also fold and twist to accomplish different functions. Imaging RNA is challenging because of the extremely small size. Very sensitive and powerful imaging systems are necessary to see RNA in a lab setting.
Researchers with an interest in double stranded RNA can isolate it in the lab by introducing cutting enzymes to an RNA sample. The enzymes will target any single strings of RNA to separate them out, leaving the double strands behind. These enzymes are available from scientific suppliers, or labs can make their own for specific research. Usually a controlled environment is necessary for cleaving RNA with enzymes, as contaminants can interrupt the process.
One function of double stranded RNA is interference or silencing. The strands can change the way a gene expresses or turn it off altogether. For dsRNA viruses, this confers a distinct advantage. The virus can enter a cell and turn genes off to protect itself, and hijack the cell to produce more copies of the virus. Viruses in this group can be difficult to treat, as they may become a moving target in the body and can fight the medications a doctor might prescribe to treat them.
Like its more well known counterpart, DNA, RNA can be sequenced with equipment that will identify the chemical chain in each strand. The nucleic acids in RNA will form complementary pairs, and this can make it easier to extrapolate a pattern. Sequencing the genetics of double stranded RNA can be important for understanding how it works in living organisms, which will allow researchers to develop antiviral drugs to target viruses that carry this unique genetic payload.