Reticulocytes are expressed as a percentage in a total of 1000 RBCs.
Tube fill capacity
500 μL for Microtainer™ (capillary) specimens
Lavender-top (EDTA) tube
Invert tube immediately 8 to 10 times once tube is filled at time of collection.
Causes for Rejection:
Hemolysis; specimen more than 72 hours old; clotted specimen; tube not filled with minimum volume; improper labeling; transfer tubes with whole blood; specimen diluted or contaminated with I.V. fluid; specimen drawn in any anticoagulant other than EDTA; specimen received with plasma removed
Evaluate erythropoietic activity which is increased in acute and chronic hemorrhage, and hemolytic anemias; evaluate erythropoietic response to antianemic therapy
Caution should be exercised with recently transfused patients (reticulocytes may decrease on a dilutional basis due to transfusion).
Patients receiving a large number of blood transfusions
Reticulocytes stained with a fluorescent reagent can be differentiated from mature red cells and other cell populations by light scatter, direct measurements, and opacity characteristics when using an automated hematology analyzer equipped with reticulocyte counting technology.