Description: Perfusion is a continuous culturing method in which cells are either retained in the bioreactor or fed back into...Perfusion is a continuous culturing method in which cells are either retained in the bioreactor or fed back into it. The harvested medium thus contains no cells, resulting in higher cell concentrations and product yields in the reactor while still reducing the working volume. This also prevents the risk of cell washout due to excessively high dilution rates (D).
The standard features of integrated pumps are often insufficient for carrying out perfusion bioprocesses. Connecting additional, external pumps requires a bioreactor with additional analog inputs and outputs. To ensure that the external pump can communicate with the bioreactor, it helps to order the pump directly from the bioreactor manufacturer. Also, connecting one or more scales makes gravimetric feeding an option for precise nutrient addition over long periods of time.
Regularly feeding additional nutrient medium keeps cells well supplied throughout the long perfusion process, increasing yields significantly and ensuring product quality. The pump for adding medium can either be controlled from the bioreactor directly or using a speific bioprocess software. A major advantage of the latter is that it can save individual feeding profiles and to use them again. Plus, bioprocess software can use parameters such as cell concentration to control the process of pumping medium in and out.
The advantage of being able to freely select the operating mode for the bioreactor's integrated pumps is that the pumps can then be reconfigured quickly and easily. If using CO2 to regulate the pH of a cell culture, operators could simply press a button to convert the acid pump to an analog feed and/or harvest pump. Eliminating the need for an additional, external pump reduces investment costs and saves space in the lab.
A large number of available sensors, such as viable cell density and biomass sensors, opens up the possibility of continuous monitoring for critical parameters. If cell concentrations are too high, monitoring the biomass concentration online allows researchers to remove cells through a process known as cell bleeding, thereby improving productivity. The use of sensors to measure metabolite concentrations reduces the risk of toxic by-products accumulating within the bioreactor.
Copyright © 2026 Biostream All rights reserved.
