Abstract:
Detection of lead present in a sample, comprising the steps of: (a) adding a lead recovery agent to an assay solution containing lead from the sample; (b) adding to the assay solution a disulfide enzyme which is inhibited in the presence of lead; and (c) correlating the activity of the disulfide enzyme to the amount of lead in the sample. The lead recovery agent, preferably a lead chelating agent, enhances the sensitivity and accuracy of the assay such that the assay can be readily automated for detection of lead in whole blood using commercially available automation systems.
Abstract:
The present invention includes novel rubella assays employing a Rubella virus capture reagent and a solid phase material containing a reaction site comprising a polymeric cation substance. A test sample suspected of containing Rubella antibody may be contacted with the capture reagent to form a capture reagent/analyte complex. The complex is then contacted to the positively charged solid phase to attract, attach, and immobilize the capture reagent/analyte complex.
Abstract:
Methods and test kits for detecting the presence of an analyte in a test sample on a molecule-by-molecule basis by using scanning probe microscopy, in which the test sample suspected of containing the analyte of interest is exposed to a test piece to which an analyte specific substance has been attached, and the test piece is scanned by scanning probe microscopy to determine the presence or absence of the analyte.
Abstract:
This invention presents novel assay methods employing a capture reagent, involving a first binding member typically conjugated to a polymeric anion substance, and a solid phase material containing a reaction site comprising a polymeric cation substance having a nitrogen content of at least about two percent. In one embodiment a test sample suspected of containing the analyte of interest may be contacted with the capture reagent to form a charged capture reagent/analyte complex. The complex is then contacted to the oppositely charged solid phase to attract, attach, and immobilize the capture reagent/analyte complex. The use of a polycationic substance, having a nitrogen content of at least about two percent (excluding the counter ions), to prepare a suitably charged solid phase provides a solid phase that can be subjected to a greater extent of manipulation, such as multiple washes, without losing the capability to attract and retain the capture reagent.
Abstract:
The present invention includes novel assays and reagents using a capture reagent, involving a specific binding member attached to a polymeric anionic substance, and a solid phase material containing a capture or reaction zone including a polymeric cationic substance. A test sample suspected of containing the analyte of interest may be contacted with the capture reagent to form a charged capture reagent/analyte complex. The complex is then contacted to the oppositely charged solid phase to attract, attach, and immobilize the capture reagent/analyte complex. With an appropriate indicator reagent, sandwich, competitive and indirect assays can be performed. Preferably, the indicator reagent includes a nonspecific binding blocker to reduce the nonspecific binding between the indicator reagent and the solid phase, without interfering with the reaction between the capture reagent and the solid phase. Suitable nonspecific binding blockers include unbound or free polyanionic materials such as dextran sulfate, heparin, carboxymethyl dextran, carboxymethyl cellulose, pentosan polysulfate, inositol hexasulfate or beta -cyclodextrin sulfate.
Abstract:
A cyanide-free method and reagent for determining the concentration of total hemoglobin in a whole blood sample accurately in less than 10 seconds comprising a ligand selected from the group consisting of imidazole, imidazole derivatives, N-hydroxyacetamide, N-hydroxyl amine, pyridine, oxazole, thiazole, pyrazole, pyrimidine, purine, quinoline, and isoquinoline, and a surfactant with strong erythrolytic capability selected from the group consisting of lauryl dimethylamine oxide and octylphenoxy polyethoxyethanol. The reagent pH is adjusted to about 11 to about 14. Rapid mixing of the reagent with a blood sample leads to the formation of a stable chromogen whose absorbance can be measured between 540 and 550 nm. The cyanide-free reagent is ideal for use on an automated high through-put clinical hematology analyzer.
Abstract:
The present invention includes novel digoxin assays employing a capture reagent, involving a first binding member conjugated to a polymeric anion substance, and a solid phase material containing a reaction site comprising a polymeric cation substance having a nitrogen content of at least about two percent. A test sample suspected of containing the analyte of interest may be contacted with the capture reagent to form a charged capture reagent/analyte complex. The complex is then contacted to the oppositely charged solid phase to attract, attach, and immobilize the capture reagent/analyte complex.
Abstract:
Assays for the determination of multiple analytes which may be present in a test sample by using different short-lived and long-lived chemiluminescent labels and integrating the generated chemiluminescence signal and time-discriminating the short-lived and the long-lived components of the signal generated. Also provided are assay kits which contain these short-lived and long-lived chemiluminescent compounds.
Abstract:
A method and article for conducting a chemiluminescent reaction in which a reaction conduit is provided having a unique configuration for enhanced chemiluminescent signal production and detection. The conduit is preferably provided with a plurality of folds defining multiple substantially different flow paths for reactants flowing therethrough. The method and article are suitable for use in diagnostic assays employing chemiluminescent labels.
Abstract:
This invention presents novel reagents, separation techniques and assay procedures which allow both the indicator and the capture reagents to be in solution to avoid problems of slowed reaction kinetics. The separation procedure involves a soluble capture reagent, comprising a specific binding member attached to a charged substance, and a insoluble solid phase that is oppositely charged with respect to the charged substance included in the capture reagent. A test sample suspected of containing the analyte of interest is mixed with the capture reagent to form a charged capture reagent/analyte complex. The reaction mixture is contacted to the oppositely charged solid phase to attract, attach, and separate the capture reagent/analyte complexes and any unreacted capture reagent from the reaction mixture. With an appropriate indicator reagent, i.e., a second specific binding member which is conjugated to a label capable of producing a detectable signal, both sandwich and competitive assays can be performed.