| Separating nucleated cells from red blood cells in liquid specimens is achieved by red cell lysis (using ammonium chloride or other solutions). The ghost red cells are removed in the subsequent washing steps. White cells can be stained with antibodies prior to or after red cell lysis. In rare instances, red cells fail to lyse. This may be the result of increased numbers of reticulocytes (e.g., specimens harboring a red cell disorder such as a hemoglobinopathy or thalassemia) or increased lipids in the serum（红细胞无法裂解的原因：网织红增多或血浆中的脂质增高等）. The unlysed red cells can be electronically removed from analysis, however, by using antiglycophorin antibody and a gating procedure. The red cell lysis procedure is preferred to density gradient methods (e.g., Ficoll-Hypaque) because it allows cells to be maintained close to their native state. Density gradient methods are based primarily on the buoyant density of normal lymphocytes. Because neoplastic cells do not necessarily share the same density as normal lymphocytes, the density gradient methods, despite their ability to remove erythrocytes, mature granulocytes, and dead cells, can result in excessive loss of critical cells. This effect is especially undesirable for samples with a low content of neoplastic cells. In addition, selective population losses in the CD8 subsets can also occur with density gradient techniques. |
Powered by Discuz! X3.5
© 2001-2024 Discuz! Team.
