Improvements in single-use systems have allowed implementing high-density cultures in standard work flows. The current study shows integration of the Thermo Scientificâ„¢ HyPerformaâ„¢ Single-Use Bioreactor (S.U.B.) and the XCellâ„¢ ATF6 Single-Use (SU) System to achieve high-density cultures. Current results are compared against similar cultures using a stainless steel ATF6 system. The S.U.B. was able to support high-density cultures (>40E06 cells/mL) without modification to standard single-use components and maintained proper operating parameters. Scale-up criteria for both S.U.B. and ATF are provided using standard components. The data show that the S.U.B. and ATF can be used in a high-density seed train or as a production vessel system.