or fittings 9 for introducing or recovering a fluid 2 or exhausting a gas 8 or introducing gas 10 through a sparger 4 fig1 further shows the bag with two rows of seals 3 to create three compartments the left compartment 12 the middle compartment 11 and the right compartment 1 the sparger 4 is positioned in the middle compartment 11 the bag is placed on a support surface 5 further containing heating element 6 and a rolling means 7 to rock the support surface 5 fig1 b shows that the bioreactor is rocked to the left and fig1 c shows the bioreactor rocked to the right the flexible the bag 3 may be made from one or more sheets of thin e g having a thickness of between 0 1 and 0 2 millimeters polyethylene film secured together to define a compartment for receiving the fluid preferably the film used is clear or translucent although the use of opaque or colored films is also possible turning now to fig2 and as noted in the foregoing description the two rows of proportionally spaced seals create three compartments by keeping the rows of seals closer to the middle of the bag a middle compartment is created which is just large enough to contain the sparger the seal 3 may be in the shape of a dot or a dash and the two rows having staggered positions of seals to force the fluid through a distorted path the sparger 4 includes a porous surface attached to the gas inlet 10 the sparging surface can be made from stainless steel.