There are many different ways to prepare the fat for injection into Brazilian butt lift. In my hands if I harvest of 3000 mL of fat with the liposuction I’ll end up with about a 3rd 1000 mL of fat to eject the buttocks. Of this I expect about 65 to 70% of the fat to survive in the best case scenario. So that will give about a 700 mL change in the buttocks.
Some people centrifuge the fat, spin the fat, strain the fat and others like me let the fat sit in separate on its own. Another controversy is whether or not exposing the fat to air kills the fat. Another consideration is whether or not to add antibiotics to the fat before injecting.
There is no definitive method of that preparation. Each doctor uses his own experience, information he learned at conferences and what works best in his or her hands to try to give the best result to his patients as he can.