Affiliations: Union International Contre le Cancre Telepathology Consultation Center, Institute of Pathology, Charite, Berlin, Germany
Abstract: Static DNA cytometry is one of the few quantitative techniques, which have been successfully applied for diagnostic pathology. Having introduced and defined minimum requirements for this technique, it plays now-a-days a significant role in confirming or ruling out malignant tumours of various origins. In this article, some basic aspects of this technique are described. The following prerequisites are used: a) all nuclei of “normal” human cells which display the same position within the cell cycle contain the same amount of DNA; b) all human cells repeat the cell cycle with the same velocity; c) the cell cycle can roughly be divided into threeseparated stages, namely resting cells (G0), multiplication stage (S-phase), and reorganization stage (mitosis, doubled DNA content); d) cells undergoing degradation or apoptosis are negligible for reference cells. By use of these prerequisites, the following parameters can be derived: a) the number of reference cells at a cell cycle stage I (1,2,3) is proportional to the duration of the cell cycle stage I; b) the cell cycle stage I of the reference cells can be calculated from the absolute DNA content and the frequency distribution of the cell cycle stages (I-III); the absolute DNA content of reference cells can be computed from the frequency distribution of reference cells within the different cell cycles. For non-reference cells, similar derivatives hold true: a) the amount of additive/missing DNA in non-reference cells is proportional to the amount of DNA of reference cells measured at the same cell cycle stage; b) the additive/missing amount of DNA of non-reference cells can be derived from the DNA distribution of reference cells and that of non-reference cells. The significance of these derivatives for application of DNA cytometry is discussed.
Keywords: Static DNA cytometry, cell cycle, standardization, DNA content