Limiting dilution assays for the determination of immunocompetent cell frequencies. I. Data analysis
Taswell, C.
Journal of Immunology 126(4): 1614-1619
1981
ISSN/ISBN: 0022-1767 PMID: 7009746 Document Number: 181681
A statistical method was developed for the analysis of experimental data from limiting dilution assays. Formulas for the estimation of the frequency of immunocompetent cells within a test population were derived by the statistical methods of weighted averaging, likelihood maximization and .chi.2 minimization. Equations for the latter 2 were solved by Newton's method of iterative approximation. Estimates obtained by these methods were more valid than those obtained by least squares (LS) fitting as judged by the .chi.2 test and as established by Monte Carlo experiments. .chi.2 minimization was chosen as the preferable estimation method with maximum accuracy and precision (minimum bias and variance) for standard frequency determination; likelihood maximization was used only for the confirmation of results. When data from previously published experiments were reanalyzed, both results and conclusions differed significantly from those originally obtained by LS fitting, thus demonstrating the importance of using proper data analysis methods. In conjunction with the use of available calculators of microcomputers, the method presented here provides a simple and rapid procedure for the valid determination of immunocompetent cell frequencies.