Sartorius and Repligen launched an integrated bioreactor system that incorporates Repligen’s XCell® ATF upstream intensification technology into Sartorius’ Biostat STR® bioreactor designed to simplify intensified seed train and N perfusion implementation for biopharmaceutical manufacturers. The Biostat STR contains an embedded XCell ATF hardware and software module offering predefined advanced control recipes with integrated Process Analytical Technology (PAT). This system was created to provide users a streamlined way to control cell growth and improve cell retention in perfusion processes without using a separate cell retention control tower.