Radioactive determination of serum thyroxine
AssigneeBio-Rad Laboratories, Inc.
InventorsCharles F. Shannon, Robert V. Dahlstrom
Life of this patent
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Abstract
A method for determining serum thyroxine (T-4) in which the T-4 is first separated from the serum by adsorption onto a montmorillonite clay and then competitively bound by exogenous thyroxine binding globulin in the presence of a known amount of radioactive T-4. The competitively bound serum T-4 and radioactive T-4 is separated from the unbound serum T-4 and radioactive T-4 by passage through an ion exchange resin column. The serum T-4 concentration is determined by measuring the amount of bound radioactive T-4 and referring to a standard curve.
Claims10
In the determination of thyroxine ("T-4") in blood serum including the steps of separating T-4 from serum, competitively binding a portion of said separated T-4 with thyroxine binding material in the presence of a known amount of radioactive T-4, separating radioactive T-4 bound by said thyroxine binding material from unbound radioactive T-4, and measuring the amount of bound or unbound radioactive T-4 whereby serum T-4 concentration may be determined therefrom, the improvement comprising:
- executing said step of separating T-4 from serum by contacting the serum with an effective amount of a montmorillonite clay under acidic conditions to adsorb the serum T-4 thereon, separating said montmorillonite clay from said serum, and then separating adsorbed T-4 from said clay, by introducing said clay into an alkaline solution, whereby said T-4 is freed from said clay.
A method for the determination of thyroxine ("T-4") in blood serum comprising:
- separating T-4 from serum by adsorbing the T-4 onto a montmorillonite clay in acidic, wherein said clay is employed in the amount of about 10 mg. per 0.0-0.3 ml. of serum, separating the clay with the adsorbed T-4 from the remainder of the serum, adding said clay with adsorbed T-4 to an alkaline solution and then adding a thyroxine binding material containing thyroxine binding material and a preselected amount of radioactive T-4, the T-4 eluting from said clay into said alkaline solution and competing with said radioactive T-4 for the binding sites on said thyroxine binding material, separating the thyroxine binding material with serum T-4 and radioactive T-4 bound thereto from unbound serum T-4 and unbound radioactive T-4, and measuring the amount of bound or unbound radioactive T-4 whereby serum T-4 concentration may be determined therefrom.
A method for the determination of thyroxine ("T-4") in blood serum comprising:
- separating T-4 from serum by adsorbing the T-4 onto bentonite clay in acidic solution, wherein about 10 mg. of said clay is employed for from 0.0-0.3 ml. of serum, separating the clay with the adsorbed T-4 from the remainder of the serum, adding said clay with adsorbed T-4 to an alkaline solution and then adding a thyroxine binding material containing thyroxine binding material in a preselected amount of radioactive T-4, the T-4 eluting from said clay into said alkaline solution and competing with said radioactive T-4 for the binding sites on said thyroxine binding material, separating the thyroxine binding materials, serum T-4 and radioactive T-4 bound thereto from unbound serum T-4 and unbound radioactive T-4 by passing the combination thereof through a column of anion exchange resin which is a 50-100 mesh styrene-divinyl benzene anion exchange resin of 8% cross linkage, of dimensions to retain unbound T-4 and radioactive T-4 while permitting bound T-4 and radioactive T-4 to flow therethrough, and measuring the amount of bound or unbound radioactive T-4, whereby serum T-4 concentration may be determined therefrom.
Dependencies are inferred from the claim text.