Software selection criteria

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... 

Statistical analysis demonstrates which input parameters are important contributors to output parameters [10]. IMP statistical software (SAS, Cary, NC) can be used to analyze data and generate separate analyses for each response variable of interest [61]. A difference of 3 SDs often is selected as the criterion for signihcance corresponding to a 95% conhdence level [61], and the test acceptance criteria range typically are set as the mean plus/minus 3 SDs (industry standard) [91]. 

The April 2001 version of the CCSD database was searched using the Windows software Conquest 1.2. The database was searched for nonionic compounds containing Pb with an R-factor <0.05 and no disorder. Lead-to-donor distance criterion was set for 0-3.50 A. A subsearch was done to select for compounds with Pb(II). A total of 295 compounds were found. 

Maximum wavelength is a suitable criterion for quantification because the main response, concentration vs. units of absorbance, depends on chromophore units and the molecular absorption coefficient. The HPLC equipment is usually linked to software that programs various channels of signal output in order to select the best maximum wavelength, which is usually not known. However, if it is well known then various channels can be used for evaluation of the absorbance ratio, which is an additional criterion for the identification procedure involving comparative measurements using ultrapure analytical standards and real samples. This topic is discussed in detail below in the section on Identification and Quantification Procedures Using Distinct Standards. ... 

Most modern instrumentation will meet these requirements. During the last 20 years or so the hardware of most manufacturers has become comparable in reliability, performance and durability. The ease with which chromatograms (and spectra in PDA detection) can be evaluated, therefore, should be the major criterion for selecting a new HPLC system. The ease of software handling and its capabilities appear to be the most important issues of concern. 

The team decided that the system software should be selected from a source that was well-established in the field of technical information. In addition, if one software and one command language could be used for the entire system, i.e., both text and chemical structure, it would be advantageous to the technical community. Because the thesaurus, a hierachical list of controlled terms, was the key to the text or document file, thesaurus software was also necessary. Search software for chemicals had to have the capability to search by substructure or full structure, by name, by compound number, by molecular formula, and by class descriptor. Continuity in both systems support and staff was a very important consideration. Another criterion was that the system be kept up-to-date with enhancements resulting from ongoing research in information science. 

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