Abstract: The present invention relates to the substantial elimination of errors attributable to carryover microspheres, doublets, or misclassification of microsphere subsets. The present invention is based upon passing a sufficient minimum number microspheres through the flow analyzer during an assay run.

Abstract: A process, a test kit, calibration standards, and the method of preparing such standards as useful for the qualitative and/or quantitative determination of total solid phase- or microparticle-immobilized, amine-containing reactants such as proteins is provided. The operating principle of the invention is distinct from a classical immunoassay based on antibody-antigen immune interaction or from standard calorimetric proteins assays of soluble proteins and allows the detection of as low as attogram (10−18 gm) levels of total analyte per microparticle.

Abstract: A method and apparatus for providing a zero dead time for flow analyzers, flow cytometers, and other measurement devices. A circular buffer is used to store data from a flow analyzer in a plurality of data storage areas, until it is convenient to implement more time consuming data processing procedures. User specified parameters, including sampling rate and/or sampling period, size and number of data storage areas, size of the circular or other buffer, signal-to-noise threshold, order of processing when a plurality of Digital Signal Processors (DSPs) is used, and fixed trailing distance, are used to provide flexible and convenient operation by a user. The probability of missing a rare event occurring within the laser beam or other light beam of a flow analyzer or other measurement device is reduced to zero.

Abstract: This invention provides a novel fluorescent particle including a core or carrier particle having on its surface a plurality of smaller polymeric particles or nanoparticles, which are stained with different fluorescent dyes. When excited by a light source they are capable of giving off multiple fluorescent emissions simultaneously, which is useful for multiplexed analysis of a plurality of analytes in a sample. The coupled complex particles carrying on their surface fluorescent nanoparticles, methods of preparing such polymer particles, and various applications and methods of using such particles are claimed.

Abstract: The invention relates to a method for the preparation of lactic acid and calcium sulphate, in which (a) an aqueous solution that contains lactate is reacted with sulphuric acid at a temperature that is essentially higher than the transition temperature of calcium sulphate dihydrate (CaSO4.2H2O), with the formation of a mixture that contains calcium sulphate hemihydrate and lactic acid, (b) the mixture from step (a) is subjected to at least one recrystallization step at a temperature that is essentially lower than the transition temperature of calcium sulphate dihydrate, with the formation of a precipitate of calcium sulphate dihydrate and an aqueous solution of lactic acid, and (c) the precipitate of calcium sulphate dihydrate is separated off from the aqueous solution of lactic acid.

Abstract: An improved method of making a series of bead or microsphere or particle populations characterized by subtle variation in a proportion or ratio of at least two fluorescent dyes distributed within a single bead of each population is provided. These beads, when excited by a single excitation light source are capable of giving off several fluorescent signals simultaneously. A set containing as many as 64 distinct populations of multicolored, fluorescent beads is provided and when combined with analytical reagents bound to the surface of such beads is extremely useful for multiplexed analysis of a plurality of analytes in a single sample. Thus, methods of staining polymeric particles, the particles themselves, and methods of using such particles are claimed.

Abstract: A multi-analyte diagnostic system for use with a computer. The diagnostic system includes a flow analyzer including a co-planar light source-optical detector array, the flow analyzer being communicatable with the computer. The diagnostic system also includes a memory medium readable by the computer and storing computer instructions. The instructions include the following steps. A biological sample is run through the flow analyzer. The identity and quantity of at least one analyte of interest in the biological fluid is determined substantially simultaneously to the sample-running step.