Samples were tested at three different concentrations (5, 15 and 30 μg/mL). Three cell culture flasks were used for each concentration/experiment totalizing 6 different volunteers. The mutagenic potential on human cell cultures was analyzed for B. jararacussu, B. alternatus, B. atrox, B. moojeni and B. brazili crude venoms and isolated toxins (BthTX-I,

BthTX-II, BjussuMP-II and BatxLAAO). The samples were added 24 h after the initiation of the cultures. After 44 h, cytochalasin-B (4 μg/mL, Sigma) was added to the cultures. The CBMN test preparations were performed according to Fenech and Morley, 1985a and Fenech and Morley, 1985b. The analyses were carried out after 72 h. Scores were taken according to the criteria of Fenech (2000). All slides

were coded and scored blindly. Three slides were made for each flask/treatment/experiment, MDV3100 in vivo and 1000 binuclear cells were counted considering the presence or absence of micronuclei, this way making it possible to determine the genotoxic effect of venoms or isolated toxins. Based on the values obtained for the controls that contained only cells and culture media, in which the micronuclei formation mean was of approximately 1.0, mean values higher than 2 micronuclei/1000 binuclear cells (MN/1000 BN cells) were considered significant for the assayed samples. The antineoplastic drug, Cisplatin (PLATINIL®, Quiral Química do Brasil S.A.) (6 μg/mL) was used as positive control. The cytokinesis-block proliferation index (CBPI) was calculated by counting 500 cells, considering the number of nuclei (mono, bi, tri or tetranucleated). The CBPI defines whether the Everolimus concentration cultures are multiplying normally after the addition of samples. The following formula was used according

to Kirsch-Volders (1997): CBPI = [1 (mono) + 2 (bi) + 3 (tri + tetra)] / 500. This test was performed according to the methodology described by Singh et al. (1988). The lymphocytes were cultured in total blood obtained from 6 healthy volunteers and each one corresponded to one experiment. The concentration and incubation times were performed according to Marcussi 3-mercaptopyruvate sulfurtransferase et al. (2011). Three cell culture flasks were used for each treatment/experiment, and the culture period was of 7 h at 37 °C. The cells were incubated with different treatments for 4 h at 37 °C, and were then utilized to prepare the slides before the first cellular division. A cellular suspension containing approximately 105 cells/mL was used to obtain 5–8 million cells per slide. Three slides were made for each flask of each treatment/experiment, although only 100 nucleoids were evaluated per flask/treatment/experiment-volunteer, totalizing 300 nucleoids/treatment/volunteer. Approximately 60 μL of each cell culture were transferred to microtubes containing 300 μL of LMP (low melting point) agarose, for the slides preparation in triplicate.