Assuntos
Testes de Coagulação Sanguínea/instrumentação , Centrifugação/instrumentação , Autoanálise , Transtornos da Coagulação Sanguínea/diagnóstico , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Testes de Coagulação Sanguínea/métodos , Compostos Cromogênicos , Coagulação Intravascular Disseminada/diagnóstico , Fator VII/análise , Fator X/análise , Fibrinogênio/análise , Heparina/administração & dosagem , Heparina/sangue , Humanos , Tempo de ProtrombinaRESUMO
We have developed a centrifugal analyzer with both fluorescence/light-scatter and conventional absorbance optics. The instrument is used in this investigation to study the formation of antigen-antibody complexes by light scattering and turbidimetric measurements, and to develop assays for human immunoglobulins G, A, and M. Concentrations are calculated from a nonlinear least-squares fit of calibrators, and antigen excess is automatically detected from kinetic curve characteristics. Precisions and patients' results are presented, and assay sensitivity and reliability in the detection of antigen excess are compared. We also investigated the effects of centrifugal force on complex formation. Both nephelometry and turbidimetry can be very satisfactorily adapted to centrifugal analyzers. We present a model to describe the observed differences between the light-scatter and the turbidity data.
Assuntos
Imunoglobulinas/análise , Complexo Antígeno-Anticorpo , Autoanálise , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Cinética , Luz , Matemática , Métodos , Nefelometria e Turbidimetria/métodos , Espalhamento de Radiação , Espectrometria de Fluorescência , Análise EspectralRESUMO
We present a total system error evaluation of random error, based on a propagation of error analysis of the expression for the calculation of enzyme activity. A simple expression is derived that contains terms for photometric error, timing uncertainty, temperature-control error, sample and reagent volume errors, and pathlength error. This error expression was developed in general to provide a simple means of evaluating the magnitude of random error in an analytical system and in particular to provide an error evaluation protocol for the assessment of the error components in a prototype Miniature Centrifugal Analyzer system. Individual system components of error are measured. These measured error components are combined in the error expressiion to predict performance. Enzyme activity measurements are made to correlate with the projected error data. In conclusion, it is demonstrated that this is one method for permitting the clinical chemist and the instrument manufacturer to establish reasonable error limits.
