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Sickle Cell Screen
MessageHematology
Test Code
LAB339
Alias/See Also
Sickle prep, Dithionite test, Sickledex, Hemoglobin S Solubility
CPT Codes
85660
Preferred Specimen
2.5 ml. whole blood (lavender top tube, EDTA), or by fingerstick using microtainer; may combine with CBC
Minimum Volume
Lavender Microtainer EDTA (0.5 mL fills to top of 500 fill line)
Other Acceptable Specimens
One Lavender-top K2EDTA Microtainer® (Min: 300 mcL), Gray-top Sodium or Potassium Oxalate tube, Light Blue-top Sodium Citrate tube, Dark Green-top Heparin tube, Yellow-top ACD tube, or a tube containing CPD or CPDA-1.
Instructions
LAB: Hematocrit of the sample must be ≥ 15%
If the hematocrit is below 15%:
Centrifuge the sample for 5-10 minutes at 1200 rpm.
Pipet 10µl of the packed cell volume from the bottom of the tube
Add it to the Sickledex® Solubility Buffer test tube.
If the hematocrit is below 15%:
Centrifuge the sample for 5-10 minutes at 1200 rpm.
Pipet 10µl of the packed cell volume from the bottom of the tube
Add it to the Sickledex® Solubility Buffer test tube.
Transport Container
Whole blood or capillary blood at room temperature (20-26°C or 68-78.8°F) or refrigerated (2-8°C or 36-46°F). (Min: 2.0 mL whole blood or 300 mcL capillary blood)
Specimen Stability
Refrigerated (2-8°C): 45 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Insufficient volume.
Frozen specimens.
Samples submitted for patients previously determined to have a positive sickle cell test.
Frozen specimens.
Samples submitted for patients previously determined to have a positive sickle cell test.
Methodology
Sickledex method is a qualitative test and does not distinguish between Sickle Cell Disease (S/S) and heterozygous Hgb S syndromes (e.g., A/S, C/S, etc.), all positive tests should be further evaluated by hemoglobin electrophoresis.
FDA Status
Moderately complex
Setup Schedule
Sunday - Saturday.
Report Available
Same day
Limitations
False negatives may occur if:
1. Hgb S concentration is low in infants younger than 6 months of age (due to the presence of Hgb F) and in transfused patients where the Hgb S is diluted below 30%.
2. Anemia (Hgb < 15%).
3. Hgb S concentration is low in infants younger than 6 months of age (due to the presence of Hgb F) and in transfused patients where the Hgb S is diluted below 30%.
4. Anemia (Hgb < 15%). Abnormal proteins, abnormal elevations of total serum proteins (particularly gamma globulins), and hyperlipidemia.
5. Hgb CHarlem, Hgb CGeorgetown, Hgb STravis, and Hgb CZiguinchor.
6. Transfusions with Hgb S blood.
7. Extremely high hemoglobin, erythrocyte count, or leukocyte count.
8. Many Heinz bodies in unstable hemoglobin disorders after splenectom
1. Hgb S concentration is low in infants younger than 6 months of age (due to the presence of Hgb F) and in transfused patients where the Hgb S is diluted below 30%.
2. Anemia (Hgb < 15%).
3. Hgb S concentration is low in infants younger than 6 months of age (due to the presence of Hgb F) and in transfused patients where the Hgb S is diluted below 30%.
4. Anemia (Hgb < 15%). Abnormal proteins, abnormal elevations of total serum proteins (particularly gamma globulins), and hyperlipidemia.
5. Hgb CHarlem, Hgb CGeorgetown, Hgb STravis, and Hgb CZiguinchor.
6. Transfusions with Hgb S blood.
7. Extremely high hemoglobin, erythrocyte count, or leukocyte count.
8. Many Heinz bodies in unstable hemoglobin disorders after splenectom
Reference Range
Negative
Performing Laboratory
Hoag Newport
