Simultaneous detection by pulse cytophotometry of DNA, RNA, and protein in Ehrlich-ascites tumours of mice treated by combined cytostatic and radiotherapy

A staining method is presented for simultaneous imaging of double-strand of nucleic acid, single-strand nucleic acid, and protein in treated and untreated Ehrlich-ascites tumours of mice by means of pulse cytophotometry. Ascites tumours were collected of five different experimental collectives and stained. The groups: One control group, one group treated with 5-FU, thymidine, uracil, and Velbe, one group with tumours treated by cytostatics but transplanted to another host animal, one group with tumours additionally irradiated before transplantation, and one group with tumours irradiated only before transplantation. Double staining is applied using o-phthaldialdehyde and acridine orange. Evaluation of the γ histograms showed a partial synchronisation of the tumour cells in the G1 and S phase of the cell cycle and a simultaneous reduction of cell numbers in the G2 phase. Concentrations of single-strand nucleic acids in tumours receiving combined treatment are higher in the G1 and S phase than in untreated tumours while there is a relative decrease in DNA concentration. The phi parameter varies in the same sense as the DNA component so that protein synthesis can be assumed to be closely linked with protein synthesis. (orig./MG)