The invention relates, in particular, to a method for processing a biological fluid using a processing system having a first biological fluid container containing a quantity of biological fluid, a first biological fluid receiving container downstream of said first biological fluid container precharged with a quantity of gas sufficient to drain the system, and a functional biomedical device in fluid communication with the first biological fluid container and the first biological fluid receiving container, the method comprising:a) causing the precharge of gas to be transferred from the first biological fluid receiving container to the first biological fluid container andb) passing the biological fluid from the first biological fluid container, through the functional biomedical device.
