| The expression of topoisomerase II alpha is strongly restricted to proliferating cells. The topoisomerase II alpha antigen is preferentially expressed during G1, S, G2 and M phase of the cell cycle, while resting, non-cycling cells (G0 phase) lack topoisomerase II alpha. In addition, constantly proliferating cells (e.g. cell lines) react positively to topoisomerase II alpha during the entire cell-cycle. This specificity for proliferating cells might make it a useful tool for determination of the proliferative fraction in solid tumors such as mammary carcinomas and gangliomas. Note that Ki67/M1B1 is also present in G1-phase. Topo IIa is also implicated in drug resistance of tumor cells. |
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| Catalog # | T8065-10X |
| Topoisomerases change the topology of DNA via cleavage of single strand only. Suitable for use in DNA conformational analysis and topology as well as DNA repair, drug resistance, cell proliferation and leukemia studies. The double-helical configuration that DNA strands naturally reside in makes them difficult to separate, and yet they must be separated if enzymes are to transcribe the sequences that encode proteins, or if chromosomes are to be replicated. In so-called circular DNA, in which double helical segment is bent around and joined in a circle, the two strands are topologically linked, or knotted. They cannot be separated by any process that does not involve the breaking of strands. Topoisomerases catalyze and guide the unknotting of DNA. |
| Type I topoisomerases cut only one strand of DNA; type I topoisomerase of E. coli > E. coli (omega protein) relaxes negatively supercoiled DNA and does not act on positively supercoiled DNA. Type II topoisomerases cut both strands of DNA; type II topoisomerase of E. coli (DNA gyrase) increases the degree of negative supercoiling in DNA and requires ATP. It is inhibited by several antibiotics, including nalidixic acid and ovobiocin. |
| Applications and Suggested Dilutions | ELISA (For coating, order Ab without BSA) |
| Immunoprecipitation: Use Protein A.10ug/mg protein lysate. |
| Western Blotting (Ab 5ug/ml for 2hrs at RT) |
| Immunofluorescence |
| Optimal dilution determined by the researcher. |
| Positive Control | Raji cells or exponentially growing any cultured human cells. |
| Cellular Localization | Nuclear |
| Molecular Weight of Antigen | 170kD |
| Storage and Stability | May be stored at 4°C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add glycerol (25–50%) and freeze at -20°C. Aliquots are stable for at least 12 months at -20°C. 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. |
| CAS Number | n/a |
| Clone Type | Polyclonal |
| Host | Rabbit |
| Source | Human |
| Concentration | ~1mg/ml |
| Form | Supplied as a liquid in PBS, pH 7.4. Also supplied with BSA and Sodium Azide. See T8065-10. |
| Purity | Purified by Protein A affinity chromatography. |
| Immunogen | KLH conjugate of a synthetic peptide, corresponding to aa 1513-1530 (Cys-RAKKPIKYLEESDEDDLF) from the C-terminus of human topoisomerase IIa. |
| Specificity | Recognizes a 170kD protein, which is identified as topoisomerase IIa. It shows no crossreaction with Topoisomerase IIb or I. Specific for human. |
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| Important Note | This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological. |
