DNA Analysis of Malignant Salivary Gland Carcinomas: Comparison of Different Tissue Preparations and Measuring Techniques

This study correlates static and flow-cytometric analysis on paraffin-embedded and fresh material of salivary gland carcinomas. Nuclear suspensions for DNA analysis were prepared from paraffin-embedded and fresh material. Comparison of the results of static and flow cytometry on paraffin-embedded material revealed no significant correlation between DNA ploidy and S-phase value. The coefficients of variation were significantly lower for static than for flow cytometry (p<0.05). Flow-cytometric analysis on fresh and paraffin-embedded material correlated well concerning DNA ploidy, but not for the S-phase. The coefficients of variation were significantly lower for the fresh than for the paraffin-embedded material (p<0.001). Cytometric analysis on paraffin-embedded material of malignant salivary gland carcinomas should be critically evaluated. There is a need for flow-cytometric investigations on fresh material to clarify further the prognostic value of this method.