Abstract: Methods and reagents for determining the lapse of time since an acute disease event, such as the occurrence of a myocardial infarction, are presented. A serum or plasma sample is assayed to determine the concentration of two different analytes selected from the group consisting of creatine kinase-MB species and creatine kinase-BB species. From these measurements, the time of the acute event can be more accurately determined. Novel antibodies, labeled and insolubilized derivatives of these antibodies, labeled proteins, and kits containing one or more of these reagents are also described.

Abstract: Methods and reagents for determining the lapse of time since an acute disease event, such as the occurrence of a myocardial infarction, are presented. A serum or plasma sample is assayed to determine the concentration of two different analytes selected from a group of creatine kinase-MB species. From these measurements, the time of the acute event can be more accurately determined. Novel antibodies, labeled and insolubilized derivatives of these antibodies, labeled proteins, and kits containing one or more of these reagents are also described.

Abstract: A method for preparing a fecal sample for immunoassay testing comprising the steps of dispersing a sample of from 1 to less than 10 wt. % of a stool sample in an aqueous fecal test solution formulated with one or more preservatives, analyte stabilizing agents and endogenous interference reducing agents. The fecal solids are then permitted to settle to form a liquid phase substantially free from fecal solids, and the clarified liquid phase is removed to provide a test sample free from fecal solids. The fecal test solutions contain suitable stool stabilizers such as buffers and antimicrobial agents, analyte protecting agents such as proteolytic, reductive or oxidative enzyme inhibitors, endogenous assay interfering enzyme inhibitors such as a reducing agent, and non-specific binding inhibitors such as animal proteins. The stool sample should be fresh or be fresh frozen and thawed immediately before dispersion in the buffer solution.

Abstract: A quantitative immunoassay for a beta-lactam antibiotic in a sample, which may contain open and closed ring forms of the antibiotic, is disclosed. Closed-ring forms of the antibiotic in the sample are converted to open-ring protein conjugates and detected through immunospecific reaction with antibodies raised against the open-ring protein conjugate form of the beta-lactam antibiotic.

Abstract: A method for preparing a fecal sample of immunoassay testing comprising the steps of dispersing a sample of from 1 to less than 10 wt. % of a stool sample in an aqueous fecal test solution formulated with one or more preservatives, analyte stabilizing agents and endogenous interference reducing agents. The fecal solids are then permitted to settle to form a liquid phase substantially free from fecal solids, and the clarified liquid phase is removed to provide a test sample free from fecal solids. The fecal test solutions contain suitable stool stabilizers such as buffers and antimicrobial agents, analyte protecting agents such as proteolytic, reductive or oxidative enzyme inhibitors, endogenous assay interfering enzyme inhibitors such as a reducing agent, and non-specific binding inhibitors such as animal proteins. The stool sample should be fresh or be fresh frozen and thawed immediately before dispersion in the buffer solution.

Abstract: A two site cross-reaction immunometric sandwich assay method for the detection and measurement of an analyte, such as creatine phospho-kinase-MB, in serum comprising the selection of two different antibodies each of which is specific to a different analyte but each of which will cross-react with the analyte of interest. The first antibody is reacted with the unknown sample utilizing a solid-phase to bind the first antibody. Separation of the solid and liquid portions of the first reaction is accomplished and the solid portion thereof is reacted with the second antibody which is tagged. The solid portion and liquid portion of the second reaction are separated and the solid portion is tested for the tag as an indication of the presence of said analyte. With particular reference to testiong for creatine phospho-kinase-MB in human serum, the cross-reacting antibodies utilized are antibody to creatine phospho-kinase-BB and creatine phospho-kinase-MM.

Abstract: Methods and reagents for early detection of myocardial infarction determine the level of CK-MM.sub.A and the level of the combined CK-MM.sub.A and CK-MM.sub.B in a serum sample. From these measurements, the time of the acute phase can be more accurately determined. Novel anti-(CK-MM.sub.A) antibodies, anti-(CK-MM.sub.B) antibodies, anti-(CK-MM.sub.(A+B)) antibodies, labeled and insolubilized derivatives of these antibodies, labeled CK-MM isoforms, and kits containing one or more of these reagents are also described.

Abstract: A process for conducting fast, rapid two site, two step immunoradiometric tests for CK-MB.In a first series of steps, a mobile particulate solid-phase having an isoenzyme selected from the group of CK-BB and CK-MM immobilying bound on its surface is suspended in a matrix of pooled match human serum. The mixture is incubated, diluted, and centrifuged.In a second series of steps, the resulting solid is incubated with a radio labeled antibody that is specific to the isoenzyme not used in the first series of steps. Counting the radioactivity gives the amount of CK-MB in the patients serum.

Abstract: An improved radioimmunoassay test method and device based upon competitive binding test methods wherein immunoreactions are halted at a time when the rate of change of the quantity of bound radiolabeled analyte of interest is inversely proportional to the concentration of analyte of interest in an unknown sera. Based thereon, a test device is created having a single calibration curve 36 which is accurate throughout the shelf life of the device.