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Methods for MAG3 conjugation and 99mTc radiolabeling of biomolecules


The chelator mercaptoacetyltriglycine (MAG3) forms a single stable chelate with technetium-99m (99mTc) oxotechnetate. The bifunctional N-hydroxysuccinimidyl ester of mercaptoacetyltriglycine with S-acetyl protection of the sulfhydryl group may be used to conjugate MAG3 to primary amine functionalized biomolecules for the purpose of radiolabeling with 99mTc for gamma detection or single photon emission computed tomography imaging (SPECT). We report here an improved MAG3 conjugation and 99mTc radiolabeling method capable of generating high radiochemical yield and high specific radioactivity. Post-labeling purification will not be needed if the protocol is followed as presented. Apart from the preparation of reagents, the conjugation and purification requires about 4 h, while the labeling with 99mTc requires about an additional 30 min.

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Figure 1: Size-exclusion HPLC analysis of a DNA oligomer conjugated with MAG3 and radiolabeled with 99mTc (trace A).


  1. Lei, K. et al. Technetium-99m antibodies labeled with MAG3 and SHNH-an in vitro and animal in vivo comparison. Nucl. Med. Biol. 23, 917–922 (1996).

    Article  CAS  Google Scholar 

  2. Blankenberg, F.G., Vanderheyden, J.L., Strauss, H.W. & Tait, J.F. Radiolabeling of HYNIC–annexin V with technetium-99m for in vivo imaging of apoptosis. Nature Protocols 1, 108–110 (2006).

    Article  CAS  Google Scholar 

  3. Welling, M.M. et al. Infection detection in mice using 99mTc-labeled HYNIC and N2S2 chelate conjugated to the antimicrobial peptide UBI 29–41. Nucl. Med. Biol. 31, 503–509 (2004).

    Article  CAS  Google Scholar 

  4. Bogdanov, A., Jr., Tung, C.-H., Bredow, S. & Weissleder, R. DNA binding chelates for nonviral gene delivery imaging. Gene Ther. 8, 515–522 (2001).

    Article  CAS  Google Scholar 

  5. Blok, D. et al. New chelation strategy allows for quick and clean 99mTc-labeling of synthetic peptides. Nucl. Med. Biol. 31, 815–820 (2004).

    Article  CAS  Google Scholar 

  6. Liu, G. et al. Radiolabeling of MAG3-morpholino oligomers with 188Re at high labeling efficiency and specific radioactivity for tumor pretargeting. Appl. Radiat. Isot. 64, 971–978 (2006).

    Article  CAS  Google Scholar 

  7. Fritzberg, A.R., Kasina, S., Eshima, D. & Johnson, D.L. Synthesis and biological evaluation of technetium-99m MAG3 as a hippuran replacement. J. Nucl. Med. 27, 111–116 (1986).

    CAS  PubMed  Google Scholar 

  8. Okarvi, S.M. & Jammaz, I.A. Preparation of in vitro and in vivo evaluation of technetium-(99m)-labeled folate and methotrexate conjugates as tumor imaging agents. Cancer Biother. Radiopharm. 21, 49–60 (2006).

    Article  CAS  Google Scholar 

  9. Visser, G.W., Gerretsen, M., Herscheid, J.D., Snow, G.B. & Dongen, G. Labeling of monoclonal antibodies with rhenium-186 using the MAG3 chelate for radioimmunotherapy of cancer: a technical protocol. J. Nucl. Med. 34, 1953–1963 (1993).

    CAS  PubMed  Google Scholar 

  10. Yoo, T.M. et al. Technetium-99m labeling and biodistribution of anti-TAC disulfide-stabilized Fv fragment. J. Nucl. Med. 38, 294–300 (1997).

    CAS  PubMed  Google Scholar 

  11. Duncan, R.J.S., Weston, P.D. & Wrigglesworth, R. A new reagent which may be used to introduce sulfhydryl-groups into proteins, and its use in the preparation of conjugates for immunoassay. Anal. Biochem. 132, 68–73 (1983).

    Article  CAS  Google Scholar 

  12. Hnatowich, D.J. et al. Labeling peptides with technetium-99m using a bifunctional chelator of a N-hydroxysuccinimide ester of mercaptoacetyltriglycine. J. Nucl. Med. 39, 56–64 (1998).

    CAS  PubMed  Google Scholar 

  13. Vanderheyden, J.L. et al. Evaluation of 99mTc-MAG3-annexin V: influence of the chelate on in vitro and in vivo properties in mice. Nucl. Med. Biol. 33, 135–144 (2006).

    Article  CAS  Google Scholar 

  14. Winnard, P., Chang, F., Rusckowski, M., Mardirossian, G. & Hnatowich, D.J. Preparation and use of NHS-MAG3 for technetium-99m labeling of DNA. Nucl. Med. Biol. 24, 425–432 (1997).

    Article  CAS  Google Scholar 

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Correspondence to Donald J Hnatowich.

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Wang, Y., Liu, G. & Hnatowich, D. Methods for MAG3 conjugation and 99mTc radiolabeling of biomolecules. Nat Protoc 1, 1477–1480 (2006).

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