Home Biomarkers Blood Group

Blood Group

Blood group ABO RH Biomarker

Sample Needed

Collection Type: Blood

Body System

Related System: Blood group ABO RH

Overview

Blood group testing determines a person’s ABO type (A, B, AB or O) and RhD status (Positive or Negative). The test identifies antigens on red blood cell surfaces and corresponding antibodies in plasma. It is essential for safe blood transfusion, organ transplantation, pregnancy care, and forensic/identification purposes. Abnormalities are not numeric but categorical mismatches (e.g., incompatible donor/recipient) that can cause hemolytic transfusion reactions or hemolytic disease of the newborn. Blood type is genetically determined, stable over a lifetime, and varies in frequency by ethnicity and population; age and sex do not change a person’s blood group.

Test Preparation

No special preparation is required

Why Do I Need This Test

Which profile is the test included in: Blood group ABO Rh profile.
What symptoms may indicate a need for this test: need for transfusion, during pregnancy, prior to surgery, or unexplained hemolysis.
What conditions it may diagnose/monitor: transfusion compatibility, risk of hemolytic disease of the newborn, blood typing for donation/organ transplant.
What could be the reasons for abnormal levels: (categorical incompatibility) presence of unexpected antibodies, rare phenotypes (e.g., Bombay), or laboratory error.
Biological meaning of abnormal values: incompatible antigen–antibody pairing can cause immune hemolysis.
What behaviors/lifestyle can cause abnormal values: none—blood group is genetic.
What family history may indicate a need for the test: family history of hemolytic disease of the newborn, known rare blood types, or need for matched transfusion.

Run our symptom checker to see if this test is right for you

Symptom Checker

Understanding Test Results

A or B or AB or O: indicates which A/B antigens are present.
O has neither A nor B antigens.
Rh+: presence of RhD antigen; Rh−: absence.
Practical implications: O Rh− is often used as emergency red-cell donor (universal RBC donor); AB Rh+ can receive RBCs from any ABO/Rh (universal RBC recipient).
Incompatible transfusion (e.g., A recipient receiving B or AB blood) can cause acute hemolytic transfusion reactions.
An Rh− mother carrying an Rh+ fetus risks alloimmunization; anti‑D prophylaxis prevents hemolytic disease of the newborn.
Rare subgroups (weak D, partial D, Bombay phenotype) require specialized testing to avoid misclassification and transfusion risk.
Always confirm with crossmatch before transfusion.

Normal Range

Categorical not a numeric range. Valid results: A, B, AB, O; RhD: Positive (Rh+) or Negative (Rh−)

FAQs

Q: What are the 4 main blood groups?

A: The four main human blood groups are A, B, AB and O, defined by presence or absence of A and B antigens on red blood cells. Group A has A antigen (and anti‑B antibodies), B has B antigen (and anti‑A antibodies), AB has both antigens (no anti‑A/B antibodies), and O has neither antigen (both anti‑A and anti‑B antibodies). The Rh factor (positive/negative) further classifies them.

Q: What are the 7 blood types?

A: The seven commonly recognized blood types are A+, A−, B+, B−, O+, O− and AB+. These names combine the ABO groups (A, B, AB, O) with the Rh factor (positive or negative); AB− also exists but is much rarer. Blood type affects transfusion and organ-donation compatibility and is identified by laboratory blood typing.

Q: Which is better, O+ or O?

A: Neither blood type is inherently better for personal health. O-negative red cells are the universal emergency donor (can be given to anyone), making O- extremely valuable for transfusions and emergencies. O-positive is more common and can donate to Rh-positive recipients but not Rh-negative. O-negative people can only receive O-negative; Rh status also matters in pregnancy.

Q: Is O+ a universal donor or O?

A: O+ is not the universal red-cell donor O− is. O+ red blood cells can be given to any Rh-positive recipient (O+, A+, B+, AB+) but cannot be transfused to Rh-negative people. For plasma, AB types are universal donors. Because O− lacks the Rh D antigen, it can be safely transfused to all ABO and Rh combinations, making it the universal red-cell donor.

Q: What is aa genotype blood group?

A: An aa (AA) genotype means two A alleles (IAIA), producing blood group A. Red cells carry A antigen and plasma contains anti‑B antibodies. For transfusion, people with AA can receive A or O blood and donate to A and AB recipients. ABO inheritance is co‑dominant: each parent contributes one allele that determines the blood type.

Q: What is the full form of abo?

A: ABO stands for the A, B and O blood group system the classification of human blood by the presence or absence of A and B antigens on red blood cells. It defines four main types: A (A antigen), B (B antigen), AB (both A and B), and O (neither antigen). The system is essential for safe transfusions, organ transplants and pregnancy care.