BacMam™ is an increasingly popular system that facilitates delivery of heterologous DNAs to broad range of mammalian transduction targets. BacMam uses baculovirus as a vector, and has distinct advantages over other mammalian transfection methods given the large heterologous DNA carrying capacity of baculovirus (>40kbp), the uptake of baculovirus by a broad range of mammalian cell types, and the sophisticated molecular biology technologies that have evolved over the last 20 years to support generation of baculovirus expression vectors. MultiBacMam™ is the first BacMam system designed specifically to allow modular, DNA recombination based assembly of multiexpression cassettes for multiprotein co-expression in mammalian cells. MultiBacMam™ uses the same DNA recombination technologies as MultiBac™, but with mammalian promoters, and a “mammalianized” baculovirus- displaying a VSV peptide on the baculovirus surface that increases virus uptake by an order of magnitude, and a stably integrated fluorescent protein to simplify monitoring of experiments. MultiBacMam™ transfer vectors are fully synthetic, comprising only functional DNA, and as a result are small and easy to handle. The MultiBacMam™ baculovirus genome (DH10EMBacVSV) is under continuous development to remove harmful/non-essential genes (e.g. v-cath and chiA) and DNA recombination hotspots, and contains an integrated fluorescent protein expression cassette to allow for ease of monitoring virus titer. The MultiBacMam™ virus particle displays the VSV peptide on its surface to increase efficiency of entry into mammalian cells by around 1 order of magnitude compared to prior BacMam virus systems.