COMPARISON OF SULFORHODAMINE B, TETRAZOLIUM AND CLONOGENIC ASSAYS FORIN-VITRO RADIOSENSITIVITY TESTING IN HUMAN OVARIAN CELL-LINES

The radiation sensitivity of six human ovarian tumor cell lines was ev aluated using sulforhodamine B (SRB), tetrazolium (MTT) and clonogenic assays. Radiobiological parameters calculated from a linear quadratic model (SF2, alpha, beta) as well as from a single-hit multitarget mod el (D-0, D-q, n) and from the area under the dose-response curve (mean inactivation dose; MID) were compared. If the values deduced from MTT experiments were statistically comparable to those obtained from clon ogenic assays, significant differences were observed between SRB and t he two other assays that concerned the results achieved with the highe st radiation doses tested (6-8 Gy), yielding a surviving fraction of a pproximately 20%. In addition, the intra- and inter-experimental varia tion of SRB dramatically increased within this range of radiation dose s. However, up to 6 Gy, the SRB assay proved to be statistically compa rable to MTT and clonogenic assays, and allowed the calculation of SF2 , alpha and MID radiobiological parameters.