Method for assessing thyroid function

Claim 1

A method for assessing thyroid function through the indirect determination of the free thyroxine concentration of a serum sample comprising the steps of: a. adding to a column containing a crosslinked dextran gel at a pH of at least about 11 a first predetermined quantity of said serum sample and a quantity of a radioactive labeled thyroxine solution, whereby substantially all of the thyroxine from said first serum sample quantity becomes dissociated from endogenous thyroxine binding protein and at least a portion of both the resulting dissociated thyroxine and the radioactive labeled thyroxine from said quantity of radioactive thyroxine solution becomes bound to said crosslinked dextran gel, b. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby substantially all of the thyroxine binding protein from said first serum sample quantity is removed from said column, the pH of the crosslinked dextran gel environment is reduced to less than 11, and all of the thyroxine from said first serum sample quantity and all of the radioactive labeled thyroxine remaining in contact with said gel is bound to said gel, c. adding to said column a second predetermined quantity of said serum sample and a predetermined quantity of an eluting liquid containing thyroxine binding protein, whereby at least a portion of the thyroxine from said first serum sample quantity and of the radioactive labeled thyroxine bound to said gel after step (b) is dissociated therefrom and becomes bound to thyroxine binding protein from said eluting liquid or said second serum sample quantity, d. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby the thyroxine from said first serum sample quantity and the radioactive labeled thyroxine which became bound to thyroxine binding protein in step (c) are sustantially completely removed from said column, e. determining the ratio of radioactive labeled thyroxine retained in said column after step (d) to that added in step (a), and f. comparing the ratio determined in step (e) to that obtained using a reference sample representing a known thyroid status in place of said serum sample in steps (a) and (c).

Claim 2

A method for assessing thyroid function through the indirect determination of the free thyroxine concentration of a serum sample comprising the steps of: a. adding to a column containing a crosslinked dextran gel at a pH of at least about 11 a first predetermined quantity of said serum sample and a quantity of a radioactive labeled thyroxine solution, whereby substantially all of the thyroxine from said first serum sample quantity becomes dissociated from endogenous thyroxine binding protein and at least a portion of both the resulting dissociated thyroxine and the radioactive labeled thyroxine from said quantity of radioactive thyroxine solution becomes bound to said crosslinked dextran gel, b. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby substantially all of the thyroxine binding protein from said first serum sample quantity is removed from said column, the pH of the crosslinked dextran gel environment is reduced to less than 11, and all of the thyroxine from said first serum sample quantity and all of the radioactive labeled thyroxine remaining in contact with said gel is bound to said gel, c. adding to said column a second predetermined quantity of said serum sample and a predetermined quantity of an eluting liquid containing thyroxine binding protein, whereby at least a portion of the thyroxine from said first serum sample quantity and of the radioactive labeled thyroxine bound to said gel after step (b) is dissociated therefrom and becomes bound to thyroxine binding protein from said eluting liquid or said second serum sample quantity, d. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby the thyroxine from said first serum sample quantity and the radioactive labeled thyroxine which became bound to thyroxine binding protein in step (c) are sustantially completely removed from said column, e. determining the ratio of radioactive labeled thyroxine retained in said column after step (d) to that added in step (a), and f. comparing the ratio determined in step (e) to that obtained using a reference sample representing a known thyroid status in place of said serum sample in steps (a) and (c).

Claim 16

A method for both determining the total thyroxine concentration of a serum sample and assessing thyroid function through the indirect determination of the free thyroxine concentration of said serum sample comprising the steps of: a. adding to a column containing a crosslinked dextran gel at a pH of at least about 11 a first predetermined quantity of said serum sample and a quantity of a radioactive labeled thyroxine solution, whereby substantially all of the thyroxine from said first serum sample quantity becomes dissociated from endogenous thyroxine binding protein and at least a portion of both the resulting dissociated thyroxine and the radioactive labeled thyroxine from said quantity of radioactive thyroxine solution becomes bound to said crosslinked dextran gel, b. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby substantially all of the thyroxine binding protein from said first serum sample quantity is removed from said column, the pH of the crosslinked dextran gel environment is reduced to less than 11, and all of the thyroxine from said first serum sample quantity and all of the radioactive labeled thyroxine remaining in contact with said gel is bound to said gel, c. adding to said column a predetermined quantity of an eluting liquid containing thyroxine binding protein, whereby at least a portion of the thyroxine from said first serum sample quantity and of the radioactive labeled thyroxine bound to said gel after step (b) is dissociated therefrom and becomes bound to thyroxine binding protein from said eluting liquid, d. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby the thyroxine from said first serum sample quantity and the radioactive labeled thyroxine which became bound to thyroxine binding protein in step (c) are substantially completely removed from said column, e. adding to said column a second predetermined quantity of said serum sample, whereby the presence in said second serum sample quantity of unsaturated thyroxine binding protein causes at least a portion of the radioactive labeled thyroxine bound to said gel after step (d) to dissociate therefrom and become bound to thyroxine binding protein from said second serum sample quantity, f. determining the amount of radioactivity retained in said column after step (d) or (e), g. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby the thyroxine from said first serum sample quantity and the radioactive labeled thyroxine which became bound to thyroxine binding protein in step (e) are substantially completely removed from said column, h. determining the ratio of radioactive labeled thyroxine retained in said column after step (d) or (e) to that added in step (a), i. comparing the ratio determined in step (h) to ratios obtained using standard liquids containing known concentrations of thyroxine, j. determining the ratio of radioactive labeled thyroxine retained in said column after step (g) to that added in step (a), and k. comparing the ratio determined in step (j) to that obtained using a reference sample representing a known thyroid status in place of said serum sample in steps (a) and (e).

Claim 17

A method for both determining the total thyroxine concentration of a serum sample and assessing thyroid function through the indirect determination of the free thyroxine concentration of said serum sample comprising the steps of: a. adding to a column containing a crosslinked dextran gel at a pH of at least about 11 a first predetermined quantity of said serum sample and a quantity of a radioactive labeled thyroxine solution, whereby substantially all of the thyroxine from said first serum sample quantity becomes dissociated from endogenous thyroxine binding protein and at least a portion of both the resulting dissociated thyroxine and the radioactive labeled thyroxine from said quantity of radioactive thyroxine solution becomes bound to said crosslinked dextran gel, b. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby substantially all of the thyroxine binding protein from said first serum sample quantity is removed from said column, the pH of the crosslinked dextran gel environment is reduced to less than 11, and all of the thyroxine from said first serum sample quantity and all of the radioactive labeled thyroxine remaining in contact with said gel is bound to said gel, c. adding to said column a predetermined quantity of an eluting liquid containing thyroxine binding protein, whereby at least a portion of the thyroxine from said first serum sample quantity and of the radioactive labeled thyroxine bound to said gel after step (b) is dissociated therefrom and becomes bound to thyroxine binding protein from said eluting liquid, d. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby the thyroxine from said first serum sample quantity and the radioactive labeled thyroxine which became bound to thyroxine binding protein in step (c) are substantially completely removed from said column, e. adding to said column a second predetermined quantity of said serum sample, whereby the presence in said second serum sample quantity of unsaturated thyroxine binding protein causes at least a portion of the radioactive labeled thyroxine bound to said gel after step (d) to dissociate therefrom and become bound to thyroxine binding protein from said second serum sample quantity, f. determining the amount of radioactivity retained in said column after step (d) or (e), g. washing said column with an aqueous alkaline solution having a pH of less than 11, whereby the thyroxine from said first serum sample quantity and the radioactive labeled thyroxine which became bound to thyroxine binding protein in step (e) are substantially completely removed from said column, h. determining the ratio of radioactive labeled thyroxine retained in said column after step (d) or (e) to that added in step (a), i. comparing the ratio determined in step (h) to ratios obtained using standard liquids containing known concentrations of thyroxine, j. determining the ratio of radioactive labeled thyroxine retained in said column after step (g) to that added in step (a), and k. comparing the ratio determined in step (j) to that obtained using a reference sample representing a known thyroid status in place of said serum sample in steps (a) and (e).