<unk>  Erythrocyte<unk> s are newly produced red blood cells. They are slightly larger than totally mature red blood cells, and have some residual ribosomal RNA. The presence of RNA allows a visible blue stain to bind or, in the case of fluorescent dye, result in a different brightness. This allows them to be detected and counted as a distinct population. The<unk>  is used to assess whether the bone marrow is producing an appropriate response to an anemic state.<unk><unk>  should increase in response to any loss of red blood cells. It should increase within 2–3 days of a major acute hemorrhage, for instance, and reach its peak in 6–10 days. If<unk><unk>  is not raised in response to anemia, then the anemia may be due to an acute cause with insufficient time to compensate, or there is a defect with red blood cell<unk>  in the bone marrow. Marrow defects include nutritional deficiencies (i.e. iron, folate, or B12) or insufficient erythropoietin, the stimulus for red blood cell<unk> .<unk> penia, or "aplastic crisis", is the medical term for an abnormal decrease of<unk> s in the body The<unk>  may find new use as a more reliable detector of erythropoietin-doping in athletes. The use of this method is referred to as "biological passport."
Reticulocyte production index
Total iron-binding capacity
Absolute neutrophil count
Transferrin saturation
Total complement activity
Mean corpuscular hemoglobin concentration
Euglobulin lysis time
Anton blood group antigen