When do you need to use a Transfer Cap?
Transfer Caps can be used whenever you need to aseptically transfer cell culture media from one vessel to another. For example, scaling up cell culture to a larger vessel, such as a wave bag or bioreactor or adding media to a flask.
What are the differences between Inversion Fill and Bidirectional Transfer Caps?
Inversion Fill Transfer Caps use gravity instead of a pump to move cell culture media from the flask to another vessel. Simply invert the flask with Inversion Transfer Cap and let gravity do the work.
There are 4 Standard Inversion Transfer Caps available: 1/4″ Male barb connection (PN 931594), 7/16″ Male quick connect (PN 931596), 1/4″ C-flex #16 tubing (PN 931595), 7/16″ C-flex #24 tubing (PN 931598). Most Wave® systems are able to quick connect directly to the 1/4″ or 7/16″ without tubing. To ensure sterility, we recommend connecting inside the hood.
Bidirectional Transfer Caps use a peristaltic pump to transfer cell culture media between the flask and another vessel. Since peristaltic pumps can pump in either direction, the Bidirectional Transfer Cap can be used to move cell culture media from the flask to another vessel such as a wave bag or a bioreactor as well as from another vessel such as a media bag into the flask.
The standard Bidirectional Transfer Cap (PN 931614) welds to 1/4″ C-Flex 16 Tubing.
What flasks are the Transfer Caps used with?
Transfer Caps are compatible with Thomson 5L Optimum Growth Flasks. Inversion Transfer Caps can be used to transfer up 3L and Bidirectional Transfer Caps can transfer up to 4.5L. Please see our technical library for more information on these flasks and their benefits. Link
What if I need a different kind of tubing attached?
We are happy to accommodate custom orders whenever possible.
How do I know if my tubing is compatible for welding to your tubing?
The C-flex tubing that comes on the Transfer Caps is compatible with most wave and bioreactor bags. We are happy to test a sample of your tubing for welding compatibility.
Can you use the Transfer Caps with all cell lines?
The Transfer Caps are compatible with all cell lines and media types.
What are the benefits to using the Inversion Transfer Caps vs other transfer methods?
The Inversion Transfer Caps use gravity to facilitate transfer rather than pumping. Pumping applies pressure to the cells resulting in some cell death. Gravity transfer is gentle and maintains high culture viability.
Coupled with the Optimum Growth Flasks, the Transfer Caps allow for direct, sterile transfer to your next culture vessel. This eliminates the need for an intermediate transfer flask or bag.
What are the benefits to using the Bidirectional Transfer Caps vs other transfer methods?
The Bidirectional Transfer Caps use a peristaltic pump to facilitate transfer. Since peristaltic pumps move can move cell culture media in both directions, the transfer caps can be used to add media to the flask as well as move cell culture fluid out the of the flask.
Coupled with the Optimum Growth Flasks, the Transfer Caps allow for direct, sterile transfer to your next culture vessel. This eliminates the need for an intermediate transfer flask or bag.
Are the Transfer Caps single use?
Yes. When tube fusing, the tube can be clamped off, cut, and refused to a different vessel. But caps cannot be reused without risk of contamination.
Will the Transfer Caps leak?
No. Just be sure the cap is securely tightened while still in the hood.
What can I do if the transfer using the Inversion Transfer Caps is slowing down or pulling a vacuum in the flask?
First, be sure you have removed the plug from the air filter. If air has not started to flow through the air filter intake, try injecting some air with a syringe to get it started.
Be sure the flask is sufficiently elevated for gravity to work.

Thomson is not affiliated with GE Healthcare Life Sciences® or their products.