¹²⁵I

High efficiency for measurement (autoradiography, gamma counting, scintillation counting)
Most commonly used in RIA and receptor ligand binding assays
Well suited for SPA (Scintillation Proximity Assay)

60.14 days

Electron capture

Ka X-ray: 0.027 MeV (112.5%)
Kb X-ray: 0.031 MeV (25.4%)
Gamma: 0.035 MeV (6.5%)

¹³¹I

High energy gamma emissions are well suited for tissue imaging.

8.04 days

Beta decay

Gammas: 0.080 (2.6%), 0.284 (6%),
0.364 (81%), 0.637 (7.3%), & 0.723 (1.8%) Mev
X-ray: 0.030 (3.9%) MeV

Bolton-Hunter Reagent
(mono-iodinated)

Custom labeling:
¹²⁵I: NEX088
¹³¹I: NEX088A

Bolton-Hunter reagent is the N-hydroxysuccinimide ester of iodinated p-hydroxyphenylpropionic acid. The active ester acylates terminal amino groups with the iodinated p-hydxyphenylpropionic residue, effectively introducing radioactive iodine into proteins and peptides. A non-oxidative technique, it is less harsh to proteins than alternative methods.

Conjugation of terminal amino groups. Applicable to peptides and proteins containing lysine residues. The mono-iodinated form is generally recommended for most Bolton-Hunter iodinations.

Bolton-Hunter Reagent
(di-iodinated)

Custom labeling:
¹²⁵I: NEX088
¹³¹I: NEX088A

Same as mono-iodinated Bolton-Hunter Reagent

Double the specific activity (or 4400 Ci/mmol) for each molecule of reagent. Use when the extra sensitivity is important relative to decrease in stability.

Lactoperoxidase

Custom labeling:
¹²⁵I: NEX083
¹³¹I: NEX083A

Lactoperoxidase catalyzes the oxidation of iodide using hydrogen peroxide as the enzyme substrate. It is a milder oxidative technique than Chloramine-T.

Applicable to peptides and proteins naturally containing tyrosine, or chemically modified to introduce tyrosine (especially applicable if they contain easily oxidized methionine)

Chloramine-T

Custom labeling:
¹²⁵I: NEX084
¹³¹I: NEX084A

Chloramine-T (p-toluene sulfonochloramine) is an effective method of labeling a variety of proteins and peptides. This oxidative method involves exposure of the substrate to Chloramine-T in the presence of NaI, ¹²⁵I- or ¹³¹I-, for a short time and produces high specific activity proteins or peptides labeled with carrier-free radioiodine, but can be harsh.

Substitution of ¹²⁵I or ¹³¹I into tyrosine residues in oxido-reducing reaction. Applicable to peptides and proteins naturally containing, or chemically modified to introduce either tyrosine or histidine.

Exchange Labeling with Sodium Iodide
Custom labeling:
¹²⁵I: NEX086
¹³¹I: NEX086A

Appropriate leaving groups exchange with ¹²⁵I or ¹³¹I in solvents or melts. (A melt is a heated reaction performed in a solid state, without solvent.) Catalysts may improve yields and reliability as well as shorten reaction times.

Exchange aliphatic or aromatic bromide or non-radioactive iodide. Exchange aromatic amines through diazonium salts or stabilized triazenes.

IODOGEN®Reagent

Custom labeling:
¹²⁵I: NEX244
¹³¹I: NEX244A

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.

Iodogen is a water insoluble oxidizing agent which can react with ¹²⁵I or ¹³¹I to form a highly reactive mixed halogen species. This intermediate can add radioactive iodine atoms to tyrosine or histidine side chain rings.

Other Custom Methods

NEX999

Propose a specific method to 爱游戏平台注册登录 for review and, if feasible, we will use it to perform your radioiodination.