Technical Evaluation and Quotation Form
Tritium Gas Exchange Using a Hydrogen Transfer Catalyst
Tritium gas exchange using a hydrogen transfer catalyst can be
employed in labeling compounds such as carbohydrates, nucleosides, nucleotides, alkaloids,
amino acids and compounds containing benzylic protons. This technique achieves specific
activities of 1-50 Ci/mmol.
Tritium gas exchange using a hydrogen transfer catalyst includes the following:
- Exposure of your compound to the appropriate amount of carrier-free tritium gas and catalyst
- Complete removal of labile tritium
- Assay of the crude product for total activity
Exchange with Tritiated Water
Tritiated water in acidic, basic, or neutral solution can be used to label compounds such as nucleotides, pyrimidines and alkaloids. This technique usually
achieves specific activities of 0.5-30 Ci/mmol.
Exchange with tritiated water includes the following:
- Reaction of your compound with the appropriate amount of tritiated solvent
- Complete removal of labile tritium
- Assay of crude product for total activity
Exposure to Tritium Gas
Labeling by exposure to tritium gas, know as the Wilzbach method,
can be performed on some pharmaceutical and other complex compounds with satisfactory
results, however many compounds will suffer significant radiation induced decomposition
and achieve low specific activities. This method should be used only if the compound
cannot be labeled using other less destructive methods.
Gas exposure tritium labeling includes the following:
- Exposure of your compound to 15 Ci of carrier-free tritium gas
- Complete removal of labile tritium
- Assay of the crude product for total activity
MB's Ligand Labeling Service is available to researchers who
are able to provide the necessary precursor, standards, and purification systems to assist
in the custom synthesis of the radiolabeled ligand. The increased level of cooperation
between you and MB's radiolabeling staff will in most cases, result in significantly
reduced costs.
Catalytic Reduction with Tritium Gas
Catalytic reduction with tritium gas can be used to label
compounds that can be obtained in unsaturated form such as aliphatic compounds, steroids,
and peptides. This technique usually achieves high specific activities in the range of
30-60 Ci/mmol per double bond reduced and a relatively pure product.
Catalytic reduction with tritium gas includes:
- Reaction of your compound with the appropriate amount of carrier-free tritium gas and catalyst
- Complete removal of labile tritium
- Assay of the crude product for total activity
Reduction with Borohydride, [3H]-
Reduction with sodium or potassium borohydride, [
3H]- is
employed mainly in the labeling of carbohydrates. This technique usually achieves specific
activities between 1-15 Ci/mmol per carbonyl group reduced.
Reduction with borohydride, [
3H]- includes the following:
- Reaction of your compound with 100 mCi of borohydride, [3H]-
- Complete removal of labile tritium
- Assay of crude product for total activity
Catalytic dehalogenation with tritium gas can be used to label
compounds such as aromatic compounds, alkaloids, nucleosides, nucleotides, peptides,
purines and pyrimidines. This technique usually achieves specific activities of 10-30
Ci/mmol per halogen replaced.
Catalytic dehalogenation using tritium gas includes the following:
- Reaction of your halo compound with the appropriate amount of carrier-free tritium gas and catalyst
- Complete removal of labile tritium
- Assay of crude product for total activity
