BURLINGTON, Mass. -- MilliporeSigma, the U.S. and Canada Life Science business of Merck KGaA, Darmstadt, Germany, today announced the signing of a definitive agreement to acquire Mirus Bio for US$ 600 million. Mirus Bio, part of Gamma Biosciences, is a life science company based in Madison, Wisconsin, USA that specializes in the development and commercialization of transfection reagents, such as TransIT-VirusGEN®. Transfection reagents play a c…