Abstract: Objective To study the applicability of four kinds of organic solvents, dimethyl sulfoxide, acetone, methanol, isopropyl, as cosovlents in anti-tumor drug screening with zebrafish model. Methods zebrafish embryos at the stage of 12h or 24 h post-fertilization were treated with serial concentrations of each organic solvent. The state of angiogenesis，abnormality and death of the above zebrafish embryos were investigated by counting the number of intersegmental vessels and calculating rates of abnormality and death until 72h post-fertilization. Results The shape and number of intersegmental vessels of living zebrafish embryos in each organic solvent are normal and identical with the control. Abnormality and death of zebrafish embryos are not observed in 0.1% concentrations of dimethyl sulfoxide, acetone and 1 % concentrations of methanol，while rates of abnormality and death are significantly higher than the control with the increase of concentration. Abnormality and death rates of zebrafish embryos are significantly higher in 0.1% concentrations of isopropyl compared with the control. Conclusions Used as a cosolvent, the suitable concentration for dimethyl sulfoxide and acetone is below or equal to 0.1 %, and for methanol is below or equal to 1 %. Isopropyl is not fit for anti-angiogenesis drug screening with zebrafish model.

Key words: Zebrafish, Angiogenesis, Drug screening, model, Cosolvent