Protein and Virus Production ATCC Protein and Virus Production Systems match reliable, authenticated cells with their ideal media and reagents to create optimized, easy to use systems for protein expression and virus propagation. HEK Transfection System The HEK 293T/17 SF cell line is optimal for transient transfection and protein expression. The GeneXPlus transfection reagent has been optimized for use with the HEK line to reproducibly express a wide range of proteins at high levels Serum-Free VERO Cell System The new Vero-SF-ACF is adapted to grow in serum-free, animal component-free media, such as VeroPlus SFM and provide the ideal host for the in vitro propagation of viruses. Host and Packaging Cell Lines ATCC holdings include an array of host and packaging cell lines of mammalian, bacterial, and insect origin. Transfection Reagents ATCC transfection reagents are designed to transfect a broad spectrum of cell types, from easy to transfect cell lines to primary cells, iPSCs, adult stem cells, and other hard to transfect cells, with high efficiency and low cytotoxicity.