Reticulocyte Count Test

Reticulocyte Count Test

What is Reticulocyte

A reticulocyte is an immature red blood cell (RBC) that has been released from the bone marrow into the bloodstream. Reticulocytes are also known as polychromatophilic erythrocytes because they have a bluish tint when stained with certain dyes, which is due to the presence of residual ribosomal RNA.

Reticulocytes are produced by the bone marrow in response to signals from the hormone erythropoietin (EPO), which is released by the kidneys in response to low oxygen levels in the blood. Reticulocytes then mature into fully functional RBCs within 1-2 days in the bloodstream. The presence of reticulocytes in the blood is an important indicator of bone marrow function and can be used to diagnose and monitor certain blood disorders such as anemia, bone marrow disorders, and hemolytic diseases.

Reticulocytes play a crucial role in maintaining the body’s oxygen-carrying capacity. Mature red blood cells contain hemoglobin, a protein that binds to oxygen in the lungs and delivers it to the tissues throughout the body. A low reticulocyte count may indicate a decreased ability of the bone marrow to produce new red blood cells, which can result in anemia.

In addition to their diagnostic value, reticulocytes have therapeutic potential as well. In some cases, patients with anemia may receive erythropoietin therapy to stimulate the production of new red blood cells, including reticulocytes. This can help improve their symptoms and quality of life.

PLATELET COUNT ( PLT ) Blood

Clinical significance : –

The number of reticulocytes in peripheral blood is a reflection of red cell forming activity ( erythropoietic activity ) of the bone marrow . Increase in their number indicates increased activity of the marrow ( hemolytic anemia or acute blood los ) . This is known as reticulocytosis . Repeated absence or low counts of reticulocytosis . Repeated absence or low counts of Reticulocytes indicate bone marrow suppression ( Aplastic anemia ) .

Normal range : –

Adults	0. 2 to 2 %
Infants	2 to 6 %

Specimen : –

EDTA Anticoagulant or capillary heparinized blood . The specimen need not be a fasting sample . Perform the test within 2 to 3 hours of blood collection .

Principle : –

Supravital staining method is used for reticulocyte count . Blood is mixed the stain and the stain enters the cells in living condition . The RNA in the cells is precipitated by staining as dark Blue network or reticulum . Blood smear is afterwards . Since a direct count is not possible , a relative count is taken against the number of red blood cells and expressed as a percentage of red cells .

Requirements : –

1 . Grease free glass slides

2 . Test tube

3 . Pasteur pipette with rubber teats

4 . Capillary tube

5 . Test tube rack

6 . Microscope

7 . Reagent

Staining solution : it is prepared as follows

a ) Brilliant cresyl blue = 1 . 0 g

b ) Sodium citrate = 0 .4 g

c ) Sodium chloride = 0 . 85 g

d ) Distilled water to = 100 ml

Dissolve first sodium citrate in normal saline and then the dye . Filter it and Store in a plastic container . It is stable at 2 – 8 ° C .

Procedure : –

• Filter a small amount of the stain ( about 5 ml ) .
• In a test tube add two drops of blood and two drops of the stain ( by using two separate pasteur pipette ) . Mix thoroughly .
• Cover the tube with cotton plug and keep at 37 ° C for 30 minutes .
• Prepare a thin smear under the low power objective and locate a portion of the smear , where the red cells are evenly distributed .
• Change to the oil immersion objective . Reticulocytes are identified by fine, deep violet filaments and granules arranged in a network . Red cells stain pale blue . Simultaneously count reticulocytes and red cell in about 15 fields .
• Calculations

Reticulocyte percentage = Number of Reticulocytes counted × 100 / Number of red cells counted .

Sources of error : –

Staining time should not be less than 30 minutes .

Additional information : –

In the case of a low hematocrit value , large quantity of blood and in case of higher hematocrit lesser quantity of blood should be used , compared to the quantity of staining solution .