Loading, Distributing, And Expanding Cells In A Hollow Fiber Bioreactor

A method for using a bioreactor-based system, the method comprising:

• circulating a volume of fluid including a cell population through a space of the bioreactor-based system in a first direction for a first period, the space having a first orientation for the first period;
• after the first period, circulating the volume of fluid including the cell population through the space of the bioreactor-based system in a second direction that is different from the first direction for a second period, the space having the first orientation for the second period;
• after the second period, circulating the volume of fluid including the cell population through the space of the bioreactor-based system in the first direction for a third period, the space having a second orientation different from the first orientation for the third period;
• and
• after the third period, circulating the volume of fluid including the cell population through the space of the bioreactor-based system in the second direction for a fourth period, the space having the second orientation for the fourth period.