This is normally achieved by bubbling an O₂-free gas through the solution until the O₂ load has been depleted.

Keep in mind, however, that PE, Tygon, and Teflon tubing are all gas permeable, and therefore will expose your perfusing solutions to O₂ during transit.

One option to address this is to use Saran tubing, which is gas impermeant to O₂. Saran tubing is expensive and difficult to work with but can be found at Clarkson Equipment and Controls, Detroit, MI.

Another option is to 'sleeve' your perfusion lines with a larger ID Tygon tube that you blow your oxygen-free gas through. Then your gas permeant  perfusion tubing will be surrounded with an O₂-free gas and your solution will not become oxygenated.