How is bone marrow donated?

Under gen anesthesia: Donating bone marrow for transplantation entails a procedure called bone marrow harvesting. The donor is placed under general anesthesia and turned over to lie on his/her belly to expose the hip bones on the back. Multiple aspirations of bone marrow are collected (average about 1 liter) at adjacent sites on the hip bone on both sides until a particular number of cells are reached.