Value of test:
Reticulocytes are immature red cells
normally present in small numbers in the blood (up to 2%). Reticulocyte numbers increase when there is an increase in erythropoietic activity. A reticulocyte count assesses bone marrow activity, e.g. whether there is an effective erythropoietic response when there is a reduction in the number of red cells due to haemolysis or haemorrhage. A reticulocyte count is also of value in monitoring the erythropoietic response of an anaemic patient following treatment.
Principle of test
An isotonic solution of a supravital stain (i.e. one that stains living material) such as New methylene blue or brilliant cresyl blue is incubated with a few drops of blood. To detect ribosomal RNA in reticulocytes, the red cells must be stained while they are still living (not fixed). A thin preparation is made and the reticulocytes counted microscopically. Reticulocytes are recognized by the violet-blue stained granules of ribosomal RNA (reticulin) they contain.
The reticulocyte count is expressed as a percentage, or preferably in absolute numbers when an electronic analyzer RBC count is available.
See also:
Lablink 