The sickling test, also known as the sickle cell test, is a laboratory test used to diagnose sickle cell disease, (a genetic blood disorder) .

It involves taking a small sample of blood from the patient and examining it under a microscope to look for the presence of sickle-shaped red blood cells.

Therefore Sickling test is essential for differentiate the sickle cell anemia and other types of anemia. For this purpose sickling test is performed.

Sickling test principle (Sick cell anemia test)

The sickling test is usually performed by adding a small amount of a deoxygenating agent, such as sodium metabisulfite, to a sample of blood.

If the blood contains sickle cells, they will assume their characteristic shape upon exposure to the agent, which can be observed under a microscope.

Sickling test procedure using sodium metabisulphite

  1. First, add 4 to 5 drops of reducing agents (Sodium metabisulfite) to one drop of EDTA mixed blood (1:4 ratio) in a test tube and mix.
  2. Drop a sample from the test tube mixture on the slide.
  3. Cover the mixture with a coverslip.
  4. Seal the mixture and coverslip with wax or petroleum jelly, so that it prevents the entering of air.
  5. After sealing, look for sickling if negative look again for 1 to 2 hours and after 12 hours.

Sickling test Requirements

  1. Reducing agents: Sodium metabisulphite
  2. Glass slide
  3. Coverslip
  4. Wax or petroleum jelly
  5. Microscope

Sickling Test positive, negative means

Sickling test positive is an indication of HbS (Sick cell Hemoglobin).

But If sickling occurs after 1 to 2 hours or after 12 hours. It is suggestive of Sickle cell Hemoglobin Traits.

On the other side, if sickling test is negative, it mean there’s not sickle cell hemoglobin (HbS).

Sickling Test precautions

Here are some precautions for sickling test

  • Laboratory Safety: Follow standard laboratory safety protocols, including wearing appropriate personal protective equipment (PPE) such as gloves, lab coat, and safety glasses.
  • Sample Handling: Handle blood samples with care and follow proper procedures for sample collection, labeling, and transportation.
  • Reagent Storage: Store reagents according to the manufacturer’s instructions, including appropriate temperature requirements. Check the expiry dates of reagents.
  • Quality Control: Perform regular quality control checks using positive and negative controls to validate the accuracy and reliability of the test results.
  • Staff Training: Ensure that the personnel performing the sickling test are trained in the proper techniques, procedures, and safety precautions.
  1. What is sickling fluid?

    Sodium metabisulphite acts as a reducing agent. It is called sickling fluid.

  2. What is the sickling test?

    The sickling test is a laboratory test used to diagnose sickle cell disease, a genetic blood disorder.

  3. What does a positive sickling test mean?

    A positive sickling test indicates the presence of sickle-shaped red blood cells in the sample, which may indicate the presence of sickle cell disease.

  4. Can a sickling test be used to diagnose other blood disorders?

    No, the sickling test is specific to sickle cell disease and cannot be used to diagnose other blood disorders.

  5. Is the sickling test always accurate?

    The sickling test is generally accurate, but it is not always definitive, and additional tests may be required to confirm a diagnosis of sickle cell disease.

  6. How long does it take to get sickling test results?

    Sickling test results can usually be obtained within a few hours to a few days, depending on the laboratory and testing protocol used.

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