The present disclosure provides a compound having Formula (I): or a pharmaceutically acceptable salt of hydrate thereof, wherein R.sup.1, A, m, and n are as described herein, for use in conducting immunodiagnostic assays for accurately measuring concentrations of circulating vitamin D, as well as for thyroxine and related analytes, estrogen and related analytes, and testosterone and related analytes.

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A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

Methods are disclosed for determining an actual concentration of a hydrophobic haptenic analyte in an unknown sample suspected of containing the hydrophobic haptenic analyte, wherein the unknown sample is suspected of containing an interfering substance. A first assay method is conducted on an unknown sample to obtain a measured concentration of the hydrophobic haptenic analyte in the unknown sample. A second assay method is conducted on the unknown sample to obtain a concentration of the interfering substance in the unknown sample. A predetermined correction formula that utilizes the measured concentration of the hydrophobic haptenic analyte and the measured concentration of the interfering substance obtained in step (a) is applied to determine an actual concentration of the hydrophobic haptenic analyte in the unknown sample.

Methods are disclosed for determining an actual concentration of a hydrophobic haptenic analyte in an unknown sample suspected of containing the hydrophobic haptenic analyte, wherein the unknown sample is suspected of containing an interfering substance. A first assay method is conducted on an unknown sample to obtain a measured concentration of the hydrophobic haptenic analyte in the unknown sample. A second assay method is conducted on the unknown sample to obtain a concentration of the interfering substance in the unknown sample. A predetermined correction formula that utilizes the measured concentration of the hydrophobic haptenic analyte and the measured concentration of the interfering substance obtained in step (a) is applied to determine an actual concentration of the hydrophobic haptenic analyte in the unknown sample.

The invention relates, in part, to methods to prepare and use molecularly imprinted copolymer compounds. Molecularly imprinted compounds of the invention can be used to identify the presence and/or level of a target compound that the molecularly imprinted copolymer compound of the invention was imprinted to detect. Molecularly imprinted copolymer compounds of the invention can also be used in separation methods to remove or isolate a target compound that the molecularly imprinted copolymer compound was imprinted to specifically bind.

The invention relates, in part, to methods to prepare and use molecularly imprinted copolymer compounds. Molecularly imprinted compounds of the invention can be used to identify the presence and/or level of a target compound that the molecularly imprinted copolymer compound of the invention was imprinted to detect. Molecularly imprinted copolymer compounds of the invention can also be used in separation methods to remove or isolate a target compound that the molecularly imprinted copolymer compound was imprinted to specifically bind.

Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

The invention discussed in this application relates to vitamin B12-based compounds that are useful as quantitative standards, particularly for the assessment of vitamin B12 deficiency.