Abstract: An assay device and method for measuring the concentration of LDL-associated cholesterol in a blood-fluid sample are described. The method employs selective precipitation of VLDL and chylomicrons and immunoseparation of HDL from a blood fluid sample. The assay device allows the assay to be performed entirely in a flow strip format.

Abstract: To detect LSD in biological samples, antibodies are raised to LSD conjugated to a protein carrier, preferably through the indole ring. Selected antibodies are matched with an immunoassay reagent in which the LSD is conjugated in the same position to a labeling or separation means. The set of reagents can be used in immunoassays with remarkably little cross-reactivity with potential interfering substances such a chlorpromazine and ergotamine, and a low false-positive rate in a panel of clinical test samples. Also provided is a set of reagents for measuring glucuronide metabolites of LSD by immunoassay, which permits exposure to LSD to be determined over a longer diagnostic window.

Abstract: The invention relates to an assay system for the improved detection of analytes, and the ability to distinguish them from cross-reacting substances. Samples giving a positive reaction in a direct assay test are treated with a neutralizing antibody that inhibits reactivity of the true analyte, but not the interfering substance. In adsorption type confirmatory assays, the neutralizing antibody is provided in an amount sufficient to adsorb the analyte but not all of the interfering substance. When retested in an immunoassay, the neutralized sample gives a negative result if it originally contained the true analyte. Samples giving a positive reaction in both the direct and confirmatory tests are marked as containing an interfering substance. The confirmatory assay easily distinguishes the true analyte and reduces the rate of false positives, even when the interfering substance is unknown and present at high concentration.

Abstract: To improve the detection of LSD in biological samples, antibodies are raised to LSD conjugated to a protein carrier, preferably through the indole ring. Selected antibodies are matched with an immunoassay reagent in which the LSD is conjugated in the same position to a labeling or separation means. The set of reagents can be used in immunoassays with remarkably little cross-reactivity with potential interfering substances such as chlorpromazine and ergotamine, and a low false-positive rate in a panel of clinical test samples. Also provided is a set of reagents for measuring glucuronide metabolites of LSD by immunoassay, which permits exposure to LSD to be determined over a longer diagnostic window.