HIGH-DENSITY FICOLL-HYPAQUE AS AN ALTERNATIVE METHOD OF EOSINOPHIL PURIFICATION

A new method for normodense eosiniphil purification is proposed. It is based on the use of high-density Ficoll-Hypaque (density = 1.114 g mL (-1)) instead of dextran sedimentation plus standard Ficoll-Hypaque, b efore discontinuous Percoll gradient centrifugation. Eosinophils from 11 controls and 11 eosinophilic patients were studied. The density dis tribution of eosinophils was similar in both groups. However, eosinoph ilic patients showed a significant increase in the absolute count of h ypodense eosinophils. Normodense eosinophil purity and recovery were s ignificantly higher in controls as compared with eosinophilic patients (p < 0.05). High-density Ficoll-Hypaque allowed separation of mononuc lear and polymorphonuclear cells with high purity and recovery using a single centrifugation step. It also reduces one step in eosinophil pu rification as compared to the standard method. Thirdly, contrary to th e single anti-CD16 magnetic bead separation method, it allows the isol ation of normodense and hypodense eosinophils. In summary, this method is economic, reliable and permits the purification of different leuco cyte populations.