Complementary deoxyribonucleic acid (DNA) is DNA made from RNA via reverse transcription, a process involving several enzymes working together. This is in contrast to the normal reproduction of genetic material in a cell, in which enzymes work to convert DNA to RNA in order to build proteins that help the cell function. Complementary DNA, also known as cDNA, is used by the body in a variety of ways. It’s also essential for researchers.
The body uses an enzyme called reverse transcriptase, as well as DNA polymerase, to create complementary DNA. The complementary DNA only copies a portion of a strand, not a complete copy of someone’s DNA. The replication process converts RNA chains into DNA strands, which encodes genetic information in a new format. Retroviruses take advantage of this to make more copies of themselves and circulate them throughout the body.
Complementary DNA has one application in scientific research. Researchers can catalyze the conversion of RNA to DNA in culture to create copies of DNA. This can be useful when manipulating genetic material, such as when a researcher needs to or prefers to work with DNA. The conversion of RNA to DNA can reveal important details about what a strand of DNA does and how it functions.
A single strand of DNA that pairs with another, fitting the sets of base pairs together like a zipper, is also referred to as a zipper. When researchers need a large number of cloned DNA copies, this can be useful. They can use polymerase chain reaction (PCR) to separate double-stranded DNA and encourage each half to make a complementary copy, resulting in two new sets of DNA. Each set can be encouraged to divide and copy until there are enough copies of the desired DNA for the researcher to work with.
The investigation of limited genetic material, such as blood from a crime scene, is one important application for PCR and complementary DNA. Blood may not contain sufficient information to be useful in an investigation or in court. A technician can use PCR to amplify DNA so that more copies are available for testing and research. Physical anthropology benefits from PCR because it allows researchers to study the genetic code of earlier humans using fragments successfully copied with PCR techniques.