Radioiodination service
Peptides, proteins and other small molecules can be radioiodinated by us for use in our in vivo or in vitro assays. We
have experience with the following radioiodination approaches:
Chloramine-T: Cholamine-T is a simple and effective method for labeling a variety of proteins and peptides. This
oxidative method involves exposure of the substrate to chloramine-T in the presence of sodium 125-iodide followed by
HPLC or other separation techniques. It produces high specific activity proteins or peptides in good yields. However, a
drawback is that any cysteine and methionine residues in the peptide will be oxidized during the procedure.
IODO-GEN reagent: A solid phase oxidative method similar to the chloramine-T method. It is generally considered to
be milder because the reaction takes place on the surface of the oxidant, minimizing exposure to the substrate.
However, sensitive methiodine residues can still be partially oxidized in the procedure.
Lactoperoxidase: Lactoperoxidase catalyzes the oxidation of iodine using hydrogen peroxide as a substrate. It is a
milder oxidative method than chloramine-T and leaves methionine residues intact.
Bolton-Hunter reagent: Bolton-Hunter reagent is the N-hydroxysuccinimide ester of iodinated p-hydroxyphenylacetic
acid. The active ester acylates terminal amino groups with the radioiodinated p-hydroxyphenylpropinoic residue,
effectively introducing radioactive iodine into proteins and peptides. Since it is a non-oxidative technique, it is less
harsh to proteins than alternative methods. Labeled proteins and peptides retain a high degree of binding activity to
receptors.
3-[125I]iodobenzoate succinimidyl ester: This reagent is similar to the Bolton-Hunter reagent except that the
radioiodine is in the 3' position on a non-activated phenyl ring and appears have resistance in this position to the action
of in vivo deiodinating enzymes (Garg et al., 1995, Bioconjugate Chem. 6: 493-501). We have the tributyltin precursor
for synthesis of this radiolabeling group.
Oxidative radioiododestannylation: For small molecules where a tributyltin precursor is available.
Typical radioiodination fee (including HPLC or other purification of final product):
$ 2,000 - $ 4,000, depending on amount and method
Peptides, proteins and other small molecules can be radioiodinated by us for use in our in vivo or in vitro assays. We
have experience with the following radioiodination approaches:
Chloramine-T: Cholamine-T is a simple and effective method for labeling a variety of proteins and peptides. This
oxidative method involves exposure of the substrate to chloramine-T in the presence of sodium 125-iodide followed by
HPLC or other separation techniques. It produces high specific activity proteins or peptides in good yields. However, a
drawback is that any cysteine and methionine residues in the peptide will be oxidized during the procedure.
IODO-GEN reagent: A solid phase oxidative method similar to the chloramine-T method. It is generally considered to
be milder because the reaction takes place on the surface of the oxidant, minimizing exposure to the substrate.
However, sensitive methiodine residues can still be partially oxidized in the procedure.
Lactoperoxidase: Lactoperoxidase catalyzes the oxidation of iodine using hydrogen peroxide as a substrate. It is a
milder oxidative method than chloramine-T and leaves methionine residues intact.
Bolton-Hunter reagent: Bolton-Hunter reagent is the N-hydroxysuccinimide ester of iodinated p-hydroxyphenylacetic
acid. The active ester acylates terminal amino groups with the radioiodinated p-hydroxyphenylpropinoic residue,
effectively introducing radioactive iodine into proteins and peptides. Since it is a non-oxidative technique, it is less
harsh to proteins than alternative methods. Labeled proteins and peptides retain a high degree of binding activity to
receptors.
3-[125I]iodobenzoate succinimidyl ester: This reagent is similar to the Bolton-Hunter reagent except that the
radioiodine is in the 3' position on a non-activated phenyl ring and appears have resistance in this position to the action
of in vivo deiodinating enzymes (Garg et al., 1995, Bioconjugate Chem. 6: 493-501). We have the tributyltin precursor
for synthesis of this radiolabeling group.
Oxidative radioiododestannylation: For small molecules where a tributyltin precursor is available.
Typical radioiodination fee (including HPLC or other purification of final product):
$ 2,000 - $ 4,000, depending on amount and method
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Preclinical contract research services
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