Bioreactor bags

Bioreactor overview

Bioreactors are vessels used to grow the cells of animals or plants under controlled conditions. The in vitro growth of cells requires an appropriate medium. To ensure good performance during cell culture in bioprocessing, conditions such as temperature, pH, and osmotic pressure must be carefully managed.

Bioreactors come in different configurations to support wide use in life science research and biopharmaceutical manufacturing. Some bioreactors are designed to be used again and again, while others are single-use systems.

Single-use vs. multiple-use bioreactors

Multiple-use bioreactors are stainless steel vessels that are reusable after thorough cleaning and sanitization. Single-use systems utilize sterile (usually gamma irradiated), disposable bioreactor bags that minimize the risk of introducing contaminants from the environment or from a previous bioreactor run.

The key differences between single-use bioreactors and stainless steel bioreactors are:

• Cleaning and sanitization: Stainless steel models require systems for cleaning in place (CIP) and sterilization in place (SIP).
• Scales: Stainless steel systems may range from small scale up to 20 000 L to allow large-scale manufacture of biologics, while single-use models are smaller and range from benchtop models up to around 2000 L.
• Flexibility: Single-use models have a faster turnaround time to allow more production batches – of one or multiple biologics.
• Waste: Single-use models utilize disposable bioreactor bags that become plastic waste. However, stainless steel vessels require large amounts of water and heat for cleaning and sanitization.
• Facility footprint: Single-use bioreactor systems are designed to be used with process intensification strategies to enhance efficiency. Smaller vessel sizes compared with stainless steel versions translate to smaller footprints.

Bioreactor bags FAQs

Here are answers to some frequently asked questions.

Bioreactor bags are disposable bags used to hold cell culture media, cells, and other components in single-use bioreactor systems. The bags are designed for use with a rocking or stirred-tank system and come in multiple sizes and configurations.

Bioreactor bags are made from multi-layer polymer films that balance gas exchange, flexibility, and strength. It’s important to avoid introducing chemicals from the bag that might impact the cell culture in a negative way.

Single-use bioreactors have a permanent structure such as a rocker or steel support for the disposable bags that are discarded when cells are harvested.

The volumes vary widely depending on the bioreactor type and scale. Bags for rocking bioreactors typically come in sizes from 1 to 25 L, while those for stirred-tank models come in volumes up to 2000 liters.