||Mammalian tissue culture cell
||Darzacq X, Shav-Tal Y, de Turris V, Brody Y, Shenoy SM, Phair RD, Singer RH. In vivo dynamics of RNA polymerase II transcription. Nat Struct Mol Biol. 2007 Sep14(9):796-806.PubMed ID17676063
||Kimura H, Sugaya K, Cook PR. The transcription cycle of RNA polymerase II in living cells. J Cell Biol. 2002 Dec 9 159(5):777-82PubMed ID12473686
||parameter optimization of FRAP and photoactivation data in U2OS 200 copy gene array. LacI gene integrated into Human U2OS osteosarcoma cells. (Primary Source) Photobleaching
||Ref researchers used Human U2OS osteosarcoma cells and arrived at elongation speed of 0.4±0.08 kb/min. This result is in accordance with Primary source (in Chinese Hamster cells) result that RNA polymerase's average residence time in random positions of the nucleus is about 20 min, corresponding to an elongation speed of 0.7 kb min^-1 for an average transcription-unit size of 14 kilobases.