In last decades, immunotherapies became more and more significant as a cancer treatment method. Many in vivo and in vitro studies have been conducted in the literature in order to determine the appropriate diagnostic and treatment methods for cancer. During the development of therapeutic vaccines, determination of vaccine concentration which is the beginning step of in vivo studies, is critical for the healthy progression of the studies. Breast cancer which occurs by uncontrolled proliferation as a result of exposure of healthy cells in breast tissue to factors such as DNA damage, UV, radiation, carcinogens and, various chemicals has a huge portion among the cancer types. In this study, for the first time, antigens generated by two different antigen preparation methods (autoclaving, freezing-thawing) using AU-565 / MCF-7 cell lines. Then, antigens derived from human breast cancer cell lines were applied alone and with different adjuvants (Polyoxidonium, Freund’s) to the J774 macrophage cell culture system and the L929 fibroblast cell line in order to investigate immunostimulant activity and cytotoxicity via Griess reagent and MTT test respectively. At the end of the 48th hour, the cell viability well will be examined and the most appropriate antigen-adjuvant combination and its concentration for vaccine preparation were determined. Among the antigen preparation methods, it was determined that the freeze-thaw method was more effective than the autoclave method, and the antigens prepared by the freeze-thaw method from the AU-565 and MCF-7 cell lines showed the highest immunostimulatory activity at a concentration of 160 µg/ml. Among the adjuvants, the immunostimulant effect of Freund's adjuvant was found to be higher. In the light of these results, the optimal vaccine concentration against breast cancer and the viability analysis of these concentrations were determined. All in all, it is thought that antibodies obtained from in vivo studies using the most appropriate antigen preparation method and the most appropriate vaccine concentration can be used in the diagnosis and treatment of breast cancer.