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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
Approval req'd? no
Available Stat? No
Test code RETH
Performed by? Hematology
Sendout? no
Price range $$
In House Availability 24 hours/ 7 days
Principle Whole blood sample is mixed with a reticulocyte reagent containing a nucleic acid dye (oxazine 750). RNA in the reticulocyte is stained and the erythrocytes are isovolumetrically sphered and fixed. Stained cells are detected and counted with an automated analyzer (ADVIA, Siemens), using a flow cytometry method.
Interpretation INTERPRETATION: The number of circulating reticulocytes is proportional to erythropoietic activity. In steady state hemolysis, the degree of reticulocytosis is proportional to the rate of hemolysis, and inversely proportional to the lifespan of the RBC.

CLINICAL SIGNIFICANCE: Increased reticulocyte count may be found after hemorrhage, in hemolytic anemias, and after treatment of anemia with hematopoietic substances. Decreased reticulocyte count in anemia indicates bone marrow suppression.
Container type EDTA (lavender top) tube
Amount to Collect 3 mL (minimum 1 mL)
Collection Instructions Heparin and citrate anticoagulated bloods are not acceptable.
Sample type EDTA anticoagulated whole blood
Min. Volume 1 mL
Normal range
Adults: Conventional Units SI Units
Relative: 0.5 - 2.0% 0.005 - 0.02
Absolute: 20 - 100 x 103/mcL 20 - 100 x 109/L

At birth: 2.5 6.5 %, (SI Unit: 0.025 - 0.065 %) falling to adult level by the end of the second week of life.
Stability Stable for 24 hours if stored at 20-30°C.
CPT coding 85045
Last Updated 11/20/2010 1:02:18 PM
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