An optimal concentration range of dimethyl sulfoxide used in mouse lymphoma assay

Objective: To investigate the cytotoxicity and genotoxicity of dimethyl sulfoxide( DMSO),and an applicable range of concentration used in mouse lymphoma assay( MLA). Methods: DMSO purchased from Tedia( DMSO-I) and Sigma( DMSO-II),respectively,were compared at final concentrations of 0. 5%,1. 0%,2. 0% and 4. 0% without the metabolic activation of S9. The cytotoxicity and mutation frequency( MF) of tk gene induced by both DMSO subjected to a 3 h treatment in L5178 tk+ /-cells were statistically analyzed. Results: For both batches of DMSO,1% showed the lowest cytotoxicity( 20%),while 4% exhibited the highest( 37%).MF triggered by 1% DMSO was similar to that of the blank control,however MF ratios were significantly increased by other concentrations( P 0. 05 or 0. 01). Conclusion: 1% is the optimal concentration for DMSO as a solvent applied in the L5178 Y tk+ /-cell line and micro-well plates based MLA test.