TK1, also known as thymidine kinase, is an enzyme, a phosphotransferase (a kinase): 2-deoxythymidine kinase, ATP-thymidine 5-phosphotransferase. It is present in two forms in mammalian cells, TK1 and TK2. Thymidine kinases have a key function in the synthesis of DNA and thereby in cell division, as they are part of the unique reaction chain to introduce deoxythymidine into the DNA. Deoxythymidine is present in the body fluids as a result of degradation of DNA from food and from dead cells. Thymidine kinase is required for the action of many antiviral drugs. It is used to select hybridoma cell lines in production of monoclonal antibodies. In clinical chemistry it is used as a proliferation marker in the diagnosis, control of treatment and follow-up of malignant disease, mainly of hematological malignancies. Source: Recombinant protein corresponding to aa1-234 of human TK1, fused to His-tag at N-terminal expressed in E. coli. Molecular Weight: ~28.0kD Amino Acid Sequence: MGSSHHHHHH SSGLVPRGSH MGSHMSCINL PTVLPGSPSK TRGQIQVILG PMFSGKSTEL MRRVRRFQIA QYKCLVIKYA KDTRYSSSFC THDRNTMEAL PACLLRDVAQ EALGVAVIGI DEGQFFPDIV EFCEAMANAG KTVIVAALDG TFQRKPFGAI LNLVPLAESV VKLTAVCMEC FREAAYTKRL GTEKEVEVIG GADKYHSVCR LCYFKKASGQ PAGPDNKENC PVPGKPGEAV AARKLFAPQQ ILQCSPAN Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.