Blood Group Testing – Kit, Principle, and Procedure

Blood Group Testing determines a person’s blood type based on the presence or absence of specific antigens and antibodies in the blood. The blood test involves mixing a sample of blood with antibodies against type A and B blood. Common blood types are A, B, AB, or O, along with Rh-positive or Rh-negative. A blood sample is collected, and antibodies react with A, B, and Rh antigens to identify the blood group. Results help ensure safe blood transfusions, and organ transplants, and manage pregnancy risks.

What is Blood Group Testing?

Blood group testing, also known as blood typing, is a diagnostic procedure that determines an individual’s blood group based on the presence or absence of specific antigens and antibodies in the blood. The two main systems used for blood typing are the ABO system and the Rh factor. In the ABO system, blood is categorized into four types: A, B, AB, and O, and the Rh factor further defines blood types into positive (+) or negative (-).

Blood testing is important for medical procedures as it ensures compatibility for blood transfusions, identify potential risks of adverse reactions, and for organ transplantation. As of July 2023, 45 recognized blood group systems contain 360 red cell antigens. These systems are genetically determined by 50 genes.

Blood Group Chart

There are 4 blood groups present. The blood group chart is shown below:

Blood Grouping Principals

Blood is a fluid connective tissue that circulates throughout the body and is responsible for transporting oxygen, nutrients, hormones, and waste products. It is also important for maintaining homeostasis, immune response, and clotting. Blood is composed of 55% plasma and 45% formed elements including red blood cells, white blood cells, and platelets.

1. Red Blood Cells (RBCs): RBC transports oxygen throughout the body.
2. White Blood Cells (WBCs): WBC are an important part of the immune system and defends against infections.
3. Platelets: Platelets aid in blood clotting and prevents excessive bleeding.
4. Plasma: It forms liquid component of blood and carry nutrients, hormones, and waste products.

Blood grouping also known as a ABO Blood Group system is based on the presence or absence of specific antigens and antibodies in the blood. Karl Landsteiner discovered the ABO blood group system in 1901.  The two most important blood group systems are the ABO system and the Rh system.

• ABO System
  • Blood is classified into four main groups: A, B, AB, and O, based on the presence or absence of antigens (A or B) on red blood cells.
  • Individuals inherit one ABO gene from each parent, resulting in specific blood types.
  • Blood type O has neither A nor B antigens, A and B types have their respective antigens, and AB type has both.
• Rh System
  • Rh factor (Rhesus factor) determines whether blood is Rh-positive or Rh-negative.
  • If the Rh factor is present, the blood type is positive (e.g., A+, B+), and if absent, it is negative (e.g., A-, B-).
  • Rh factor inheritance is independent of ABO blood group inheritance.
• Antibodies and Agglutination
  • Anti-A and anti-B antibodies in the plasma react with foreign antigens.
  • Agglutination (clumping) occurs when antibodies react with incompatible antigens.
  • Testing involves introducing blood to anti-A, anti-B, and anti-Rh antibodies to observe reactions.
• Compatibility
  • Blood transfusions and organ transplants require compatibility between donor and recipient blood types to prevent adverse reactions.
• Universal Donor and Recipient
  • Type O negative (O-) is considered a universal donor as it lacks A, B, and Rh antigens.
  • Type AB positive (AB+) is a universal recipient as it can receive blood from any type.

Blood Group Test Procedure

Blood Group testing method is used to determine the blood group of the individual.

Aim

The primary objective of this experiment is to comprehend the fundamental principles of the ABO blood group system and determine our individual blood group and type.

Materials Required

The material required for testing blood group are:

(All equipment is available in a blood test toolkit)

• Toothpicks
• Blood sample
• Alcohol Swabs
• Lancet
• Clean glass slide
• Sterile cotton balls
• Biohazard disposal container
• Monoclonal Antibodies (Anti-A, B, and D)

Procedure

Procedure to determine the blood group is as follows:

• Take a clean glass slide and mark three circles on it.
• Unpack the monoclonal antibodies (MAB) kit. Add Anti-A to the first circle, Anti-B to the second circle, and Anti-D to the third circle using a dropper.
• Place the slide aside without disturbance.
• Clean the ring finger with alcohol swabs and rub gently near the fingertip, the collection site for the blood sample.
• Use the lancet to prick the ring fingertip and wipe off the initial blood drop.
• Allow the blood to fall onto the three circles of the glass slide by gently pressing the fingertip as blood emerges.
• Apply pressure on the pricked site to stop blood flow, using a cotton ball if necessary.
• Gently mix the blood sample with a toothpick and wait for a minute to observe the reaction results.

Precautions

Precautions during blood group testing includes:

• Sterilization of equipment to prevent contamination.
• Verify accurate patient identification to prevent sample mix-ups.
• Dispose of biohazardous materials properly in designated containers.
• Handle samples and reagents gently during mixing to avoid errors.

Results of Blood Group Testing

Blood group testing results for A, B, AB, and O blood types are determined by observing agglutination reactions with specific antibodies. The possible outcomes of the blood test are:

• Blood Type A:
  • Anti-A Reaction: Positive (indicating the presence of A antigens).
  • Anti-B Reaction: Negative (indicating the absence of B antigens).
• Blood Type B:
  • Anti-A Reaction: Negative (indicating the absence of A antigens).
  • Anti-B Reaction: Positive (indicating the presence of B antigens).
• Blood Type AB:
  • Anti-A Reaction: Positive (indicating the presence of A antigens).
  • Anti-B Reaction: Positive (indicating the presence of B antigens).
• Blood Type O:
  • Anti-A Reaction: Negative (indicating the absence of A antigens).
  • Anti-B Reaction: Negative (indicating the absence of B antigens).
• Anti-D (Rh Factor) Reaction:
  • Positive: Presence of the Rh factor, determining a positive blood type (e.g., A+, B+).
  • Negative: Absence of the Rh factor, determining a negative blood type (e.g., A-, B-).

The table showing the different types of blood groups along with its Rh factor.

Blood Type	A	B	O	AB
Rh-positive	A+	B+	O+	AB+
Rh-negative	A-	B-	O-	AB-

Blood Group Testing Kit

Blood group testing kits are available for use in various settings, including healthcare facilities, laboratories, and even for personal use at home. These kits typically include the necessary components for ABO and Rh blood typing. While professional laboratories often use more sophisticated methods, such as serological techniques, home blood typing kits are designed for simplicity and ease of use.

It includes reagents like anti-A, anti-B, and anti-Rh antibodies, along with a testing card or slide, lancets for blood collection, and mixing tools. Users collect a small blood sample, apply it to the testing device, mix with reagents, and observe for clumping reactions to determine the ABO and Rh blood type. While it is suitable for basic blood typing, professional laboratory testing is recommended for critical medical situations.

Conclusion – Blood Group Testing

Blood group testing involves a small blood sample and using reagents to determine ABO and Rh blood types. The process includes applying the blood to a testing device, mixing with specific antibodies, and observing for clumping reactions. These tests are crucial for medical procedures such as transfusions, ensuring compatibility between donors and recipients and organ transplants. While blood group testing kits offer convenience, professional laboratory testing is advisable for critical situations.

FAQs – Blood Grouping Testing

What is Blood Group Test Name?

The blood group test is commonly referred to as “ABO and Rh typing” or “Blood Typing.”

What is a Blood Group test?

Blood group testing, also known as blood typing, is a test that determines a person’s blood type based on the presence of certain proteins, called antigens, on the surface of red blood cells.

Which Blood group is called the Universal Donor and Universal Recipient?

Blood group O negative (O-) is considered the universal donor, and blood group AB positive (AB+) is considered the universal recipient.

How many Types of Blood Groups are there?

There are four main blood groups: A, B, AB, and O. Each group can be either RhD positive or RhD negative, which means there are eight blood groups in total.

What determines Blood Type?

Blood type is determined by a pair of genes, one from each parent. These genes determine the presence or absence of certain antigens on the surface of your red blood cells.

What’s the Rarest Blood Type?

Rh-null is one of the rarest blood types in the world, with fewer than 50 people having it. It is also known as golden blood.

Why is it Important to know Blood Types?

Blood typing is a method for determining your blood type. It’s important to know your blood type in case of an emergency, such as an accident, illness, or injury that requires a blood transfusion.