Alkali Denaturation Test for HbF Explained Simply
Doctors use this test to measure fetal hemoglobin. It works well in newborns and thalassemia cases. Therefore, labs rely on it often.
The test exploits a key difference. Adult hemoglobin (HbA) denatures quickly in strong alkali. Fetal hemoglobin (HbF) resists denaturation strongly. As a result, HbF stays soluble longer.
Perform the test in these steps. First, mix blood with dilute sodium hydroxide (0.1 N NaOH). Next, add the mixture to a buffer solution. Then shake it gently for one minute. After that, add ammonium sulfate or ethanol to precipitate denatured proteins.
Centrifuge the solution quickly. The supernatant contains undenatured HbF. Measure its absorbance at 540 nm or 415 nm. Compare it to the total hemoglobin level. Thus, calculate the percentage of HbF easily.
The method gives reliable results fast. Normal newborns show high HbF (up to 70–90%). Adults usually have less than 1% HbF. However, β-thalassemia major patients often show 10–90% HbF.
This test helps diagnose conditions accurately. It distinguishes HbF from other hemoglobins. Moreover, it remains useful despite newer methods like HPLC. Labs still perform it widely.
Run the test carefully. Handle alkali safely. You get clear HbF values quickly. Therefore, doctors confirm diagnoses faster.