Quality control study by the French Cytometry Association on flow cytometric DNA content and S-phase fraction (S%)

Abstract

Clinical use of flow cytometric (FCM) DNA analysis requires effective quality controls. Thirty‐two laboratories with various degrees of FCM experience participated in the first phase of a quality control program organized by the Association Française de Cytométrie. All received diskettes containing ten list‐mode files and ten histogram files that were derived from FCM analysis of various unfixed tumor specimens. A total of 610 responses on DNA ploidy and cell cycle were obtained with three different DNA analysis softwares: CellFit used by (44% of responses), MultiCycle (44%), and ModFit (12%). After statistical analysis, 31% of the responses were excluded from the final analysis for precise reasons. The groups were too small to carry out a valid analysis of the slight differences in the percentage of cells in the DNA synthesis phase (S%) between CellFit and MultiCycle. To estimate the influence of gating on the final cell‐cycle results, five of the histogram files were derived from corresponding list‐mode files, but the participating laboratories were unaware of this. A good correlation (r = 0.98) was obtained for S% values in the five paired files. The fact that 31% of the responses had to be excluded clearly reflects inadequate training in the use of these analysis softwares and, in some cases, a failure to grasp the biological meaning of the results. In contrast, the laboratories fulfilling consensus recommendations obtained remarkably homogeneous results, showing that standardization is feasible. © 1996 Wiley‐Liss, Inc.

Improved DNA flow cytometric, DNA ploidy, and S‐phase reproducibility between 15 laboratories in analysis of breast cancer using generalized guidelines

“…It has therefore been suggested that quality control programs should be performed in this field (2,19 -21). Attempts to improve the standardization have been done in our group, as well as in other groups (22)(23)(24)(25)(26)(27). These attempts have shown that it is logistically possible to organize a quality control program with many laboratories for standardizing DNA FCM analysis.…”

Twenty years of external quality assurance in clinical cell analysis — A tribute to Jean‐Luc D'Hautcourt

“…In the '90s, several EQA studies on DNA ploidy and Sphase assessment were undertaken (21)(22)(23). Jean Luc D'Hautcourt was also active in this application for many years.…”

DNA-synthesizing enzymes in breast cancer (thymidine kinase, thymidylate synthase and thymidylate kinase): Association with flow cytometric s-phase fraction and relative prognostic importance in node-negative premenopausal patients

“…[1][2][3][4] Reproducible SPF results have been obtained by well-trained laboratories adhering to common recommendations. [5][6][7] Another approach for consideration of cell proliferation is the measurement of enzymes involved in DNA synthesis. For pyrimidine synthesis, two pathways have been identified.…”