Method for determining steroids in human body liquids
AssigneeCornell Research Foundation, Inc.
InventorsSongja Pang, Maria I. New
Life of this patent
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Abstract
A micromethod for the determination of steroids in human body liquids, in particular blood, is disclosed. A small sample of the liquid is transferred to a sheet of absorbing material, e.g., filter paper. A disc of the impregnated paper, containing the dried sample, in eluted with an aqueous solvent, e.g., a buffer solution. Without separating the paper from the elute, the latter is extracted with an organic solvent. A steroid-containing residue is recovered from the organic extract and is subjected to a conventional radioimmunoassay. The method is particularly suited for the detection of disorders with elevated steroid levels such as congenital adrenal hyperplasia in newborn infants by determining the 17.alpha.-hydroxy-progesterone concentration in small blood samples.
Claims16
A method for determination of a steroid contained in a sample of a human body liquid which comprises the steps of:
- (a) transferring said liquid sample onto a sheet of material which is capable of uniformly absorbing said liquid sample;
- (b) drying the sample-containing sheet;
- (c) treating a portion of the dry sample-containing sheet, which is equivalent to a predetermined amount of the sample, with an aqueous solvent in order to obtain a mixture wherein the dried sample of human body liquid is substantially redissolved in the aqueous solvent;
- (d) extracting said aqueous mixture with a volatile organic solvent capable of dissolving said steroid in order to obtain an organic extract containing said steroid dissolved therein;
- (e) separating at least a portion of said organic extract from said aqueous mixture;
- (f) recovering a residue containing the steroid from said organic extract;
- (g) contacting said residue with an aqueous solution of an agent, said agent being capable of selectively binding said steroid, in the presence of a radioisotopically labeled form of the steroid, whereby part of said labeled steroid and part of said unlabeled steroid present in the sample, are bound by forming a complex with said binding agent, separating said bound steroids from unbound steroids in said aqueous solution and measuring the radioactivity of at least said separated binding agent-steroids-complex or said unbound steroids to determine the concentration of said hormone as a function of the measured radioactivity.
A combination for the determination of a steroid hormone in a sample of a human body liquid, comprising:
- (a) a first container having therein an absorbing paper adapted for absorbing the sample of the body liquid;
- (b) a second container, containing a first reagent which comprises a radioisotopically labeled form of the steroid hormone;
- and
- (c) a third container, containing a second reagent comprising an antiserum for the steroid hormone.
Dependencies are inferred from the claim text.