Nuclear DNA the bases are held together by hydrogen bonds. Nuclear DNA and mitochondrial DNA differ in many ways, starting with location and structure. Nuclear DNA is located within the nucleus of eukaryote cells and usually has two copies per cell while mitochondrial DNA is located in the mitochondria and contains 100-1,000 copies per cell. The structure of nuclear DNA chromosomes is linear with open ends and includes 46 chromosomes containing 3 billion nucleotides. Mitochondrial DNA chromosomes usually have closed, circular structures, and contain for example 16,569 nucleotides in human. Nuclear DNA is diploid, ordinarily inheriting the DNA from two parents, while
Pfu DNA polymerase and (1991)Patent 5,545,552 over "Pfu" itself was granted in August 1996. Pfu DNA polymerase "Pfu" DNA polymerase is an enzyme found in the hyperthermophilic archaeon "Pyrococcus furiosus", where it functions to copy the organism's DNA during cell division. In the laboratory setting, "Pfu" is used to amplify DNA in the polymerase chain reaction (PCR), where the enzyme serves the central function of copying a new strand of DNA during each extension step. "Pfu" DNA polymerase has superior thermostability and proofreading properties compared to "Taq" DNA polymerase. Unlike "Taq" DNA polymerase, "Pfu" DNA polymerase possesses 3' to 5' exonuclease proofreading activity,