Evaluation of an alternative to the Kolmogorov-Smirnov test for flow cytometric histogram comparisons

Background: The Kolmogorov-Smirnov test is a valid statistical test for com paring distributions that has been recommended for flow cytometric histogra m analysis. However, this test ii frequently found to be too sensitive for flow cytometric histogram comparisons. Here, a parametric alternative to th e Kolmogorov-Smirnov test is proposed that is based on fitting suitable mod els to flow cytometric data. Methods: Several flow cytometric histograms de rived from cell surface immunophenotyping for intercellular adhesion molecu le-1 (ICAM-1) on K562 cells were analyzed using numerical modeling. The pre diction intervals derived from the modeling were used for decision making. Results: The residuals after peak fitting flow cytometric data are normally distributed and this permits the use of the prediction limit methodology. The usefulness of the approach for analyzing flow cytometry histograms is e xamined and the method is shown to avoid the "sensitivity" disadvantages as sociated with the Kolmogorov-Smirnov test. Conclusions: The prediction limi t method is a viable alternative to the Kolmogorov-Smirnov method. (C) 1999 Elsevier Science B.V. All rights reserved.