Abstract: The present invention provides methods and compositions, e.g., kits, for assaying a vitamin D moiety in a sample, comprising or using, inter alia, a buffer that is capable of dissociating a vitamin D moiety from its binding protein and/or a buffer of acidic pH, and at least two antibodies, e.g., at least two monoclonal antibodies, that are separately conjugated to particles, e.g., latex particles, wherein at least one of said antibodies (or the first antibody) has a specific binding affinity towards the vitamin D moiety, and at least another said antibody (or the second antibody) has a specific binding affinity towards the complex formed between the first antibody and the vitamin D moiety, if present in said sample. In some embodiments, the optical change due to the agglutination reaction between the antibodies and the vitamin D moiety is measured for determination of the amount of vitamin D content in the samples. Kits and reaction mixtures for assaying a vitamin D moiety in a sample are also provided.

Abstract: The present invention provides methods and compositions, e.g., kits, for assaying a vitamin D moiety in a sample, comprising or using, inter alia, a buffer that is capable of dissociating a vitamin D moiety from its binding protein and/or a buffer of acidic pH, and at least two antibodies, e.g., at least two monoclonal antibodies, that are separately conjugated to particles, e.g., latex particles, wherein at least one of said antibodies (or the first antibody) has a specific binding affinity towards the vitamin D moiety, and at least another said antibody (or the second antibody) has a specific binding affinity towards the complex formed between the first antibody and the vitamin D moiety, if present in said sample. In some embodiments, the optical change due to the agglutination reaction between the antibodies and the vitamin D moiety is measured for determination of the amount of vitamin D content in the samples. Kits and reaction mixtures for assaying a vitamin D moiety in a sample are also provided.

Abstract: Provided herein are compositions and methods for analyzing neutralizing antibodies to SARS-CoV-2, for example, in a sample from a subject suspected of having, having, or having had (e.g., having recovered from) a SARS-CoV-2 infection, or a subject having received a prophylactic and/or therapeutic intervention for a coronavirus infection.

Abstract: The present invention provides methods and compositions, e.g., kits, for assaying a vitamin D moiety in a sample, comprising or using, inter alia, a buffer that is capable of dissociating a vitamin D moiety from its binding protein and/or a buffer of acidic pH, and at least two antibodies, e.g., at least two monoclonal antibodies, that are separately conjugated to particles, e.g., latex particles, wherein at least one of said antibodies (or the first antibody) has a specific binding affinity towards the vitamin D moiety, and at least another said antibody (or the second antibody) has a specific binding affinity towards the complex formed between the first antibody and the vitamin D moiety, if present in said sample. In some embodiments, the optical change due to the agglutination reaction between the antibodies and the vitamin D moiety is measured for determination of the amount of vitamin D content in the samples. Kits and reaction mixtures for assaying a vitamin D moiety in a sample are also provided.

Abstract: This invention generally relates to the field of vitamin D detection. In particular, the invention provides novel methods and kits for assaying a vitamin D moiety in a sample such as a biological fluid.

Abstract: The present invention provides novel methods for determining the presence or amount of a hydrolytic enzyme in a sample, based on novel substrates for the enzymes, and also provides compositions and methods that provide highly sensitive assay methods for such hydrolytic enzymes.

Abstract: The present invention provides novel methods for determining the presence or amount of a hydrolytic enzyme in a sample, based on novel substrates for the enzymes, and also provides compositions and methods that provide highly sensitive assay methods for such hydrolytic enzymes.

Abstract: The present invention provides novel methods for determining the presence or amount of a hydrolytic enzyme in a sample, based on novel substrates for the enzymes, and also provides compositions and methods that provide highly sensitive assay methods for such hydrolytic enzymes.

Abstract: The present invention provides methods for assaying a vitamin D moiety in a sample, using a water miscible organic solvent, a specific binding partner that specifically binds to said vitamin D moiety, the binding partner being different from a natural vitamin D binding protein for the vitamin D moiety, and a water soluble polymer that facilitates binding between the specific binding partner and the vitamin D moiety. Kits and reaction mixtures for assaying a vitamin D moiety in a sample are also provided.

Abstract: The invention provides electrochemical biosensors for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The invention provides methods for using the electrochemical biosensors.

Abstract: The invention provides enzymatic methods for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The methods utilizes one or two different types of oxidizing agents which selectively oxidize low-molecular weight reducing substances and high-molecular weight (mainly hemoglobin) reducing substances in blood samples, coupled with enzymatic reactions catalyzed by proteases, fructosyl amino acid oxidase. The amount of hydrogen peroxide generated in the reaction is measured for determination of percentage of glycated hemoglobin in blood samples. The invention provides kits for performing the methods of the invention.

Abstract: This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. The Hcy co-substrate conversion product may be assessed directly, or it may be assessed by further conversion of the Hcy co-substrate conversion product into another material by the action of one or more additional enzymes. A kit for assaying homocysteine based on the same principle is also provided.

Abstract: The invention provides enzymatic methods for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The methods utilizes one or two different types of oxidizing agents which selectively oxidize low-molecular weight reducing substances and high-molecular weight (mainly hemoglobin) reducing substances in blood samples, coupled with enzymatic reactions catalyzed by proteases, fructosyl amino acid oxidase. The amount of hydrogen peroxide generated in the reaction is measured for determination of percentage of glycated hemoglobin in blood samples. The invention provides kits for performing the methods of the invention.

Abstract: The invention provides enzymatic methods for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The methods utilizes one or two different types of oxidizing agents which selectively oxidize low-molecular weight reducing substances and high-molecular weight (mainly hemoglobin) reducing substances in blood samples, coupled with enzymatic reactions catalyzed by proteases, fructosyl amino acid oxidase, and peroxidase. The invention provides kits for performing the methods of the invention.

Abstract: The present invention provides novel methods for determining the presence or amount of a hydrolytic enzyme in a sample, based on novel substrates for the enzymes, and also provides compositions and methods that provide highly sensitive assay methods for such hydrolytic enzymes.

Abstract: The invention relates generally to the field of sodium and lithium ion detection. In particular, the invention provides chimeric proteins, nucleic acids encoding chimeric proteins, methods and kits for assaying for sodium ions and for lithium ions in a sample, using inter alia, a 3?(2?),5?-bisphosphate nucleotidase.

Abstract: The present invention provides compositions and methods for reversibly inhibiting S-adenosyl-L-homocysteine (SAH) hydrolase. The compounds of the present invention can be used in combination with an anti-hemorrhagic viral infection agent, an immunosuppressant, a homocysteine lowering agent, or an anti-neoplasm agent. The compositions and methods of the present invention can be used for the prevention and treatment of hemorrhagic virus infection, autoimmune diseases, autograft rejection, neoplasm, hyperhomocysteineuria, cardiovascular disease, stroke, Alzheimer's disease, or diabetes.

Abstract: The present invention provides a two-step assay for measuring myeloperoxidase (MPO) activity in a blood sample. The first step utilizes a chromogenic substrate to measure first peroxidase activity including MPO activity in the sample, whereas the second step measures non-MPO peroxidase activity in the presence of the same chromogenic substrate and a specific MPO inhibitor. Specific MPO peroxidase activity is then determined by comparing the non-MPO peroxidase activity and the total peroxidase activity. The MPO peroxidase activity obtained in this fashion may be proportional, and preferably directly proportional, to the mass of MPO in the sample. Kits for assaying MPO peroxidase activity based on the same principle are also provided.

Abstract: The invention provides enzymatic methods for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The methods utilizes one or two different types of oxidizing agents which selectively oxidize low-molecular weight reducing substances and high-molecular weight (mainly hemoglobin) reducing substances in blood samples, coupled with enzymatic reactions catalyzed by proteases, fructosyl amino acid oxidase. The amount of hydrogen peroxide generated in the reaction is measured for determination of percentage of glycated hemoglobin in blood samples. The invention provides kits for performing the methods of the invention.

Abstract: The invention provides enzymatic methods for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The methods utilizes one or two different types of oxidizing agents which selectively oxidize low-molecular weight reducing substances and high-molecular weight (mainly hemoglobin) reducing substances in blood samples, coupled with enzymatic reactions catalyzed by proteases, fructosyl amino acid oxidase, and peroxidase. The invention provides kits for performing the methods of the invention.