Risberg B, Baldetorp B, Fernö M, Hansson B, Mossberg L L, Roos G, Stål O, Thornthwaite J T, Tibell L
Department of Pathology, Medical Center Hospital, Orebro, Sweden.
Anal Cell Pathol. 1994 Jan;6(1):23-36.
In order to study interinstitutional reproducibility of flow cytometric DNA-analysis (DNA-FCM), frozen pieces from 30 consecutive breast carcinomas were analysed by 5 laboratories. Different instruments, preparation and DNA staining methods were used. A concordance in DNA-ploidy status was obtained in 26 of the 30 tumours. The discrepancy can mainly be explained by intratumoural DNA-heterogeneity since a complete agreement in ploidy status was obtained when four of the laboratories analysed the same cell suspension, where solid bits showed differing results. The sampling method seems therefore to be a crucial step for the results and needs further studies. As far as the estimation of S-phase fraction was concerned, one laboratory obtained significantly higher values compared to the other four. The correlation between the other four laboratories varied between r = 0.66-0.92.
