Isolation of Peripheral Blood Leukocytes by Ficoll Gradient Centrifugation
Freshly drawn blood was diluted with PBS to a total volume of 3ml. A volume of 6ml Ficoll-Paque (Pharmacia, 5.7g Ficoll 400 in 100ml) was centrifuged at 1000x g for 10 min at room temperature. Subsequently the blood was overlaid into the tube. The mixture was centrifuged at 1000 x g for 10 min at room temperature with no brake. Fractions were collected from the top with a Pasteur pipette (plasma and leukocytes) or with a syringe (erythrocytes). Leukocytes were washed twice with phosphate-buffered saline (PBS).