An apparatus and method for delivering oxygen to a cell culture medium is disclosed. In one embodiment, the apparatus includes a transfer chamber placed within the cell culture medium. The transfer chamber is adapted to allow the cell culture medium to come in substantial contact with a liquid chemical that is passing through transfer chamber. The apparatus further includes a vessel placed outside the cell culture medium that serves to contain and continually recharge the liquid chemical. The apparatus further includes a plurality of pumps and tubes for circulating the liquid chemical through the transfer chamber and back to the vessel. When the liquid chemical comes into contact with the cell culture medium, oxygen is transferred from the liquid chemical to the cell culture medium.