The EZ1 RNA Cell Mini Kit can be used to isolate RNA from blood after removal of the erythrocyte fraction by hypotonic lysis or Ficoll density gradient centrifugation. Please follow the protocol for purification of total RNA from cells. Appendix D in the EZ1 RNA Mini Handbook describes a method for hypotonic lysis of erythrocytes. The EZ1 RNA Cell Kit can also be used for RNA isolation from bone marrow. However, if a high number of erythrocytes are present, the leukocyte fraction should be collected as recommended above. The amount of starting material should not exceed 1x10e6 cells.