CYTOPHOTOMETRIC DNA MEASUREMENTS OF CHONDROSARCOMA - METHODOLOGIC ASPECTS OF MEASUREMENTS IN TISSUE-SECTIONS FROM OLD PARAFFIN-EMBEDDED SPECIMENS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 2  (2) , 84-92
Abstract
The methodologic prerequisites of cytophotometric DNA measurements of normal and tumor [human] cells in tissue sections obtained from paraffin blocks and preserved as archival material were investigated. The optimal time of hydrolysis in 5-N HCl at room temperature was 1 h for the different cell types analyzed. Paraffin-embedded tissues, stored for 2 decades, were still suitable for quantitative cytophotometric DNA determinations of Feulgen-stained nuclei. Different cell types in the Feulgen-stained sections could be identified with accuracy. The 90th percentile of fibroblast (internal control cells) DNA values was used as an upper limit of the diploid DNA content. By determining the number of tumor cells with DNA values exceeding this limit, nondiploid (hyperploid) tumor cell populations could be discriminated from diploid tumor cell populations. Cell population analysis of ploidy level, performed in this way, was accurate in tissue sections of 4 .mu.m. The accuracy of this analysis was not improved by increasing section thickness. The prognostic significance of hyperploidy parameter in different tumors can be assessed retrospectively.