Activity criterion

A single test will be used to determine acceptance or rejection of a test material. Once an activity criterion (such as an X score in a righting reflex test) is established, compounds are evaluated based on being less than X (i.e., negative) or equal to or greater than X (i.e., positive). As more data are accumulated, the criterion should be... 

For purposes of our discussion here, we will primarily focus on the single-stage system, which is the simplest. The approaches presented here are appropriate for use in any of these screening systems, although establishment of activity criteria becomes more complicated in successive screens. Clearly, the use of multistage screens presents an opportunity to obtain increased benefits from the use of earlier (lower-order) screening data to modify subsequent screen performance and the activity criterion. 

Those screeners uncomfortable selecting actives without reference to explicit plate controls would define activity relative to the activity of the solvent control and/or known reference compounds on each plate. Most screeners will format their libraries such that one or two columns on the plate contain the positive and negative controls. The latter are the solvent controls and the activity criterion could be determined as a fold induction or percentage inhibition relative to the solvent controls. By the inclusion of reference samples with known biological activity, one can also calculate the relative efficacy for each hit. Since the controls will be variable from plate to plate, the percentage control and efficacy values should be calculated on a plate-by-plate basis by the software, rather than as a single large batch. Evaluation of the precision and accuracy of the bioassay... 

Kinetics criterion K is used as an antioxidant activity criterion of the investigated substances. It reCbcts quantity of oxygen and their radicals which have reacted with AO (or their mixes) in a minute ... 

Criterion K is used as an antioxidant activity criterion of the investigated substances ... 

Figure 5-57. Evolution of the decohesion criterion and the source activation criterion in the slip plane for the CEPM.

Al.6.2 A Qay with an average azobenzene equivalence between 30 and 35 meets the activity criterion (see 7.3). Clay with azobenzene equivalence values outside this range is not suitable for use in this test method. 

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