Principles of screening and study design

Chapter three Principles of screening and study design... 

The design concept, basic flow physics, principle of operation, and advantages and disadvantages of vanes, sponges, and screen channel LADs (gallery arms) were outlined previously in Chapter 2. Sponges are not considered in this trade study because it was not desired to control the location of the ullage bubble. 

The sparsity of effects principle (see Box and Meyer, 1986) makes resolution III and IV fractional factorial designs particularly effective for factor screening. This principle states that, when many factors are studied in a factorial experiment, the system tends to be dominated by the main effects of some of the factors and a relatively small number of two-factor interactions. Thus resolution IV designs with main effects clear of two-factor interactions are very effective as screening... 

Since immunoassays are primarily analytical techniques, in addition to studies for a better understanding of the nature of antibody-antigen interaction, there are continuous efforts to improve immunoassay performance (e.g., sensitivity, selectivity, precision and accuracy) in terms of robustness and reliability when analysing complex samples. The present chapter attempts to summarize the most commonly used immunoassay concepts, as well as the main approaches employed for the improvement of immunoassay sensitivity, selectivity and precision. The discussion is focussed aroimd the main thermodynamic and kinetic principles governing the antibody-antigen interaction, and the effect of diverse factors, such as assay design, concentration of reactants, incubation time, temperature and sample matrix, is reviewed in relation to these principles. Finally, particular aspects on inummoassay standardization are discussed as well as the main benefits and limitations on screening vs. quantification of analytes in real samples. 

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