A simple computer programme for standard curve tracing and calculations in RIA following sigmoid patterns

Computational models in immunological methods: an historical review

The utilization of computational models in immunology dates from the birth of the science. From the description of antibody-antigen binding to the structural models of receptors, models are utilized to bring fundamental understandings of the processes together with laboratory measurements to uncover implications of these data. In this review, an historical view of the role of computational models in the immunology laboratory is presented, and short mathematical descriptions are given of fundamental assays. In addition, the range of current uses of models is explored -- especially as seen through papers which have appeared in the Journal of Immunological Methods from volume 1 (1971/1972) to volume 208 (1997). Each paper which introduced a new mathematical, statistical, or computer simulation model, or introduced an enhancement to an instrument through a model in those volumes is cited and the type of computational model noted.

Method of analysis of non-competitive enzyme immunoassays for antibody quantification

A computerized analysis of a quantitative enzyme-linked immunoadsorbent assay (EIA) using a non-specific immunoglobulin (IgG) of known concentration as the standard has been developed for measuring specific antibody levels in serum without the need for affinity purification of the positive control antibody. The computer program utilized logit-log linear regression analysis of sigmoid serial dilution curves plus a weighted least-squares best curve fit analysis and an iterative manipulation to eliminate errant data points. The EIA was performed using serial dilutions of standard and unknown antibodies, and a double sandwich technique. A comparison of antibody levels determined by EIA using non-specific IgG as a standard relative to antibody levels determined using affinity-purified specific antibody as a standard were 1.04, 0.53, 0.48, and 0.97 for four different polyclonal antibody systems. Five monoclonal antibodies to carcinoembryonic antigen gave ratios as described above of 1.07, 1.59, 1.73, 2.32, and 2.42. The corresponding antibody affinity constants (1/mol) were 1.0 X 10(8), 3.8 X 10(8), 5.5 X 10(9), 1.8 X 10(10), and 2.6 X 10(10) respectively. This method permits accurate quantification of serum antibody levels when affinity-purified antibodies are not readily available and avoids errors due to loss of antibody activity during affinity purification.

Measurement of immunoglobulin concentration in cell culture supernates by computer-assisted ELISA

The enzyme-linked immunosorbent assay (ELISA) is used extensively in immunologic research for obtaining quantitative estimates of immunoglobulin concentration in cell culture supernates. Through incorporation of a microcomputer for data acquisition, storage and rapid calculation of results, a substantial reduction in total assay time may be realized. Described here are a set of menu-driven programs written in Basic for the IBM-PC which provide advantages over existing software in simplicity, versatility and accuracy. Hardware requirements are minimal. These programs should encourage greater flexibility in terms of the size and complexity of experimental designs.

A microcomputer program for probit analysis of interleukin-2 (IL-2) titration data

IL-2 activity is commonly estimated in cell culture supernatants by an IL-2-dependent cell proliferation assay. This method is both reproducible and sensitive. However, it often appears from the literature that statistical analysis of the titration data either is disregarded or, when performed, is based on statistically incorrect assumptions. The proposed method is based on the principle of biological assay by parallel lines as applied to probit analysis of quantitative responses. The procedure has been embodied in a simple and interactive computer program which automatically estimates the IL-2 concentration in the biological sample, in terms of U/ml, and provides its standard error and confidence limits. This program is also suitable for quantitative determination of other biologically active substances that show a sigmoid dose/response relationship.