Abstract: Provided herein are methods of perfusion culturing a mammalian cell that include: providing a vessel containing a mammalian cell disposed in a first liquid culture medium having an osmolality of about 270 mOsm/kg to about 380 mOsm/kg; incubating the mammalian cell for a period of time at about 32° C. to about 39° C.; and during the period of time, continuously or periodically removing a first volume of the first liquid culture medium and adding to the first liquid culture medium a second volume of a second liquid culture medium, wherein the first and second volumes are about equal and the osmolality of the first and second liquid culture medium in the vessel is maintained at about 270 mOsm/kg to about 380 mOsm/kg over the period of time.

Abstract: The disclosure features methods that include obtaining a vibrational spectrum of a solution in a biological manufacturing system, analyzing the vibrational spectrum using a first chemometrics model to determine a value of a first quality attribute associated with the solution, analyzing the vibrational spectrum using a second chemometrics model to determine a value of a second quality attribute associated with the solution, and adjusting at least one parameter of a purification unit of the biological manufacturing system based on at least one of the values of the first and second quality attributes.

Abstract: The disclosure features methods that include obtaining a vibrational spectrum of a solution in a biological manufacturing system, analyzing the vibrational spectrum using a first chemometrics model to determine a value of a first quality attribute associated with the solution, analyzing the vibrational spectrum using a second chemometrics model to determine a value of a second quality attribute associated with the solution, and adjusting at least one parameter of a purification unit of the biological manufacturing system based on at least one of the values of the first and second quality attributes.