Cell isolation yield and purity. (A) PBMC numbers and (B) residual platelet numbers per μl of blood are shown after isolation with density gradient centrifugation in dependence of the anticoagulant used during blood collection. Each donor is represented by a colour-coded symbol (n = 5). The median is marked with a line. Use of citrate, EDTA and heparin as anticoagulant results in similar numbers of PBMC (A) and of residual platelets (B).