Immunotherapy of superficial bladder cancer by Mycobacterium bovis Calmette-Guerin (BCG) bladder instillation is used worldwide. Impaction of four lyoprotectant including trehalose, lactose, dextran and monosodium glutamate on changing in the effectiveness of BCG has been studied by measuring its cytotoxicity by the use of amido black staining. The results showed that the cytotoxicity of BCG bacilli at different concentrations against EJ138 and 5637 cell lines were independent of these lyoprotectants.
