General & BloodNo Fasting RequiredTurnaround: 24–48 hours

Hemoglobin Electrophoresis & HPLC (Thalassemia & Sickle Cell Screen)

Also known as: Hemoglobin Variant Analysis, HPLC Thalassemia Test, Sickle Cell Screen, Hb Variant HPLC, Hemoglobinopathy Screen

Parameters Measured in the Report

A breakdown of individual biomarkers and biological reference intervals typically found in your report:

Biomarker	Standard Range	Unit	What It Means
Hemoglobin A (HbA) (Major Adult Hb)	Adults: 95.0%–98.0%	%	Normal adult hemoglobin composed of two alpha and two beta globin chains (alpha2-beta2).
Hemoglobin A2 (HbA2) (HbA2 Fraction)	Normal: 2.0%–3.5% Beta-Thalassemia Trait (Carrier): 3.6%–7.0%	%	Minor adult hemoglobin (alpha2-delta2); elevation >3.5% is the diagnostic hallmark of Beta-Thalassemia Minor trait.
Hemoglobin F (Fetal Hb) (HbF)	Adults: < 1.0%–2.0% (Elevated in Thalassemia Major & HPFH: > 10%–90%)	%	Fetal hemoglobin (alpha2-gamma2); elevated in hereditary persistence of fetal hemoglobin and severe hemoglobinopathies.
Hemoglobin S (Sickle Hb) (HbS Variant)	0.0% (Absent) Sickle Cell Trait: 30%–45% Sickle Cell Disease: > 80%–90%	%	Pathological variant caused by beta-globin point mutation (Glu6Val); red cells sickle in deoxygenated capillaries.

* Note: Reference ranges may vary slightly between testing instruments and reagent kits. Always refer to the reference interval printed on your specific pathology report.

Clinical Focus

Percentage fractions of normal adult hemoglobins (HbA, HbA2, HbF) and pathological variant hemoglobin peaks (HbS, HbC, HbE, HbD) separated by High-Performance Liquid Chromatography (HPLC) or capillary electrophoresis.

Sample & Specimen

Venous blood (EDTA lavender-top tube)

Fasting Protocol

No fasting required. Must not have received a blood transfusion in the prior 3 months.

Turnaround Time

24–48 hours

What Is This Test?

Hemoglobin Electrophoresis and High-Performance Liquid Chromatography (HPLC) are the definitive analytical techniques used to separate and quantify the various structural hemoglobin variants circulating inside human red blood cells. Adult blood consists predominantly of Hemoglobin A (alpha2-beta2, >95%), with small physiological fractions of Hemoglobin A2 (alpha2-delta2, <3.5%) and fetal Hemoglobin F (alpha2-gamma2, <1%). Genetic mutations in globin genes produce **Hemoglobinopathies** — either qualitative structural variants (such as Sickle Cell Hemoglobin HbS, where red blood cells deform into rigid sickles under low oxygen) or quantitative synthesis defects (**Thalassemias**, where unbalanced globin chain production causes microcytic anemia). Identifying carrier traits (Beta-Thalassemia Minor) prevents catastrophic Thalassemia Major births through informed prenatal counseling.

Why Did Your Doctor Order This Test?

Physicians routinely prescribe the Hb Electrophoresis / HPLC in the following clinical scenarios:

Investigation of persistent microcytic hypochromic anemia (low MCV < 75 fL) that fails to improve with iron supplementation

Mandatory pre-marital and early prenatal screening in populations with high hemoglobinopathy prevalence (Mediterranean, Middle Eastern, South Asian, African, and Southeast Asian descent)

Diagnostic confirmation of Sickle Cell Disease in patients presenting with acute vaso-occlusive bone pain crises, dactylitis, or acute chest syndrome

Family history of known thalassemia major, sickle cell disease, or hydrops fetalis

Distinguishing iron-deficiency anemia from Beta-Thalassemia Minor trait (Mentzer Index < 13)

How to Prepare Before Your Test

Fasting Requirement: No fasting required. Must not have received a blood transfusion in the prior 3 months.

No fasting or special preparation required.
IMPORTANT: The patient must NOT have received a red blood cell blood transfusion in the past 90 to 120 days, as donor hemoglobin masks the patient’s true genetic variant profile.

Understanding Your Results

What higher or lower readings generally mean in clinical practice:

If Values Are Higher Than Normal

An elevated **HbA2 fraction between 3.6% and 7.0%** definitively establishes the diagnosis of Beta-Thalassemia Minor (carrier trait). If both parents carry this trait, there is a 25% risk in every pregnancy of having a child with Thalassemia Major (a severe transfusion-dependent anemia). The presence of **HbS >80%** confirms Sickle Cell Disease.

If Values Are Lower Than Normal

A normal adult profile (HbA >95%, HbA2 2.0%–3.5%, HbF <1.5%, no abnormal peaks) rules out beta-thalassemia and major hemoglobin variants. (Note: Alpha-Thalassemia trait requires specialized DNA genetic testing, as HbA2 is typically normal or slightly reduced).

Frequently Asked Questions

Why do patients with Beta-Thalassemia Minor get misdiagnosed with Iron Deficiency Anemia?

Both conditions cause small, pale red blood cells (microcytic hypochromic red cells with low MCV). However, iron deficiency shows low ferritin and responds to iron pills, whereas thalassemia minor has normal or high ferritin and does NOT improve with iron. Taking iron pills for thalassemia minor can cause dangerous iron overload.

What is the Mentzer Index in distinguishing thalassemia from iron deficiency?

The Mentzer Index is calculated from a standard CBC: MCV divided by RBC count. An index >13 suggests iron deficiency, while an index <13 strongly points toward Thalassemia Minor trait, prompting confirmation via HPLC.

Related Laboratory Tests

Tests frequently prescribed together or used as follow-up investigations:

Complete Blood Count (CBC / Hemogram)

Counts and evaluates red blood cells, white blood cells, hemoglobin, hematocrit, and platelets.

Iron Profile & Serum Ferritin

Serum Iron, Total Iron-Binding Capacity (TIBC), Transferrin Saturation (% Sat), and Stored Tissue Ferritin.

Peripheral Blood Smear Examination (PBS / Pathologist Blood Film Review)

Direct microscopic morphological evaluation of stained red blood cells (size, shape, color, inclusions), white blood cell maturity (blasts, left shift, toxic granules), and platelet morphology by a pathologist.

Medical & Diagnostic Disclaimer

This guide is published for educational and patient informational purposes only. It is not a substitute for professional medical evaluation, diagnosis, or clinical advice.

A laboratory result that falls slightly outside standard statistical reference intervals does not automatically indicate disease; conversely, a normal result does not guarantee the absence of medical conditions. Only your attending physician can interpret lab findings in the context of your medical history, physical exam, and symptoms.