RESUMEN
A microcomputer software package for determining the concentration of either the antibody or antigen from ELISA data for IBM PC compatible is presented. In the program optical densities (OD) and fluorescence obtained from 96-well ELISA plate can be input either directly, by interfacing with different brands of microplate reader such as Multiskan II Plus and Organon Teknika to the computer or manually. This software utilizes some mathematical and statistical models to fit the standard curve of each assay and interpolate analyte concentration using data from OD or fluorescence measurements. Cubic spline (Guardabasso et al., 1988), bezier and polynomial (Rodbard, 1979; Baud et al., 1991) interpolation formulas can be used to fit the data over the entire range for estimating the antibody or antigen concentration of the unknown samples whose OD or fluorescence is beyond the entire range. This software package, based on the concentration values of the analyte determined in different fluids (Núnez et al., 1994; Morales et al., 1994) and with some rules and algorithms, is used to calculate the parameters of screening and diagnostic tests such as sensitivity, specificity and predictive values (Coughlin et al., 1992). With the construction of the Receiver Operating Characteristic (ROC) curve it is possible to analyse different values of the sensitivity and specificity of the screening and diagnostic tests. A comparative statistical test for two populations that are non-normally distributed using a non-parametric Mann-Whitney test is provided. This software is an expandable tool designed for general use in clinical and experimental applications, including diagnostic and screening tests.