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- Hb S
- Hemoglobin S
- Hgb Solubility
- Sickle Cell Preparation
- Sickle Cell Solubility Test
- Sickle Cell Test
- Sickle Prep
Expected Turnaround Time
1 - 3 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Lavender-top (EDTA) tube; capillary puncture: three microhematocrit tubes. May also use blue-top (sodium citrate) tube, yellow-top (ACD) tube, or green-top (heparin) tube.
No preliminary fluid or food restriction is required.
Causes for Rejection
Specimen other than whole blood received; clotted specimen
Qualitative determination of presence of hemoglobin S; detect sickling hemoglobins; evaluate hemolytic anemia, undiagnosed hereditary anemia with morphologic (sickle-like) abnormalities on peripheral blood smear
False-positive solubility test for sickling may be due to polycythemic blood; interference by some forms of hyperglobulinemia; and a variety of abnormal hemoglobins, including I, Bart, CGeorgetown, Alexandra, CHarlem, Porto Alegre, Memphis/S, CZiguinchor, and STravis.1 Positive tests should be confirmed by hemoglobin fractionation. A positive reaction also occurs in the presence of many Heinz bodies (eg, after splenectomy), and in blood protein disorders due to precipitation of plasma proteins. False-negative solubility test reactions may occur with inadequate quantities of blood from anemic patients (hemoglobin levels <8.0 g/dL); high concentration of Hb F or of phenothiazines may inhibit the sickle reaction;1 quantities of hemoglobin S too small to detect, as at birth or with transfusions of nonhemoglobin S into patients with hemoglobin S. The appearance of hemoglobin S is genetically delayed and is not present in sufficient quantity until after three months of age. Maximum levels are not reached until about six months of age. Solubility tests are unlikely to be reliably positive until after six months of age; therefore, this test should not be used for testing neonates or children younger than six months of age.
Sodium hydrosulfite reduction
Distinction between Hb S β-thalassemia and sickle cell anemia is not always possible on clinical, hematologic, or electrophoretic grounds. Thalassemia heterozygotes have hypochromia and microcytosis, but overlap values exist. Differentiation can best be made by family or molecular pathology methods. Regional prevalence in the midwest area of Hb S β-thalassemia is estimated to be 1:23,000 of the black population. It is recommended that positive sickle cell patients be further evaluated with Hb fractionation (HPLC), Hb F studies, and family studies. Complete characterization may require sophisticated laboratory studies with DNA amplification.2
|Order Code||Order Code Name||Order Loinc||Result Code||Result Code Name||UofM||Result LOINC|
|005223||Hgb Solubility||6864-3||005225||Hemoglobin (Hgb) Solubility||6864-3|