A mixing system and method for forming bone cement by mixing liquid monomer methyl methacrylate (MMA) with a powder component comprising polymethyl methacrylate (PMMA). A container of MMA is received in a bag. The MMA is emptied from the container into the bag, and a syringe is connected to the bag in substantially leak-free manner to receive the MMA from the bag. The syringe is disconnected from the bag and thereafter connected to a receptacle housing the powder component. The MMA is then transferred into the receptacle in substantially leak-free manner.