Abstract: The invention relates to a serum-free cell culture perfusion medium comprising the medium components subgrouped into at least three separate aqueous concentrated feeds and a diluent, wherein the resulting serum-free cell culture perfusion medium is pH-adjusting to neutral pH upon mixing. Also provided is a method of preparing said serum-free cell culture perfusion medium. The invention further relates to methods of culturing mammalian cells or producing a protein of interest in perfusion culture using said serum-free cell culture perfusion medium that achieve high productivity at a low cell specific perfusion rate. The invention further relates to the use of the new and improved serum-free cell culture perfusion medium to control osmolality in a perfusion cell culture, wherein increasing osmolality results in an increase in total productivity and/or cell specific productivity by suppressing cell growth during cell culture, e.g., during production phase of perfusion cell culture.

Abstract: Provided herein are improved methods for transducing immune cells, such as T cells, with retroviral vectors to express exogenous gene products, such as chimeric antigen receptors (CARs). Provided herein are methods that increase transduction efficiency thereby increasing the percentage of immune cells in a population expressing the exogenous gene product. Associated cells, cell populations, compositions and methods of use are also provided.