Difference Between O Positive and O Negative

Main Difference – O Positive vs O Negative

O positive and O negative are the two blood types in the human blood type O. The human blood is classified under ABO blood type system. Within the ABO system, four blood types can be identified: type A, type B, type AB, and type O. The ABO blood type system is determined by three alleles; I^A, I^B, and i. The type A blood is determined by the combination of I^AI^A or I^Ai alleles. The type B blood is determined by the combination of I^BI^B or I^Bi alleles. The type AB blood is determined by the combination of I^AI^B alleles. The blood type O is determined by the presence of the recessive allele pair, ii in the genome. The human blood is also classified based on the presence of ‘Rhesus’ factor on the surface of red blood cells as Rh positive or Rh negative. The ‘Rhesus’ factor is also called the antigen D. The main difference between O positive and O negative is that Rh factor is present on the surface of the red blood cells of the O positive blood whereas Rh factor is absent on the surface of the red blood cells of the O negative blood.    

Key Areas Covered

1. What is O Positive Blood Type
      – Definition, Rh Factor, Antibodies, Matching Blood Types
2. What is O Negative Blood Type
      – Definition, Rh Factor, Antibodies, Matching Blood Types
3. What are the Similarities Between O Positive and O Negative Blood Types
      – Outline of Common Features
4. What is the Difference Between O Positive and O Negative Blo0d Types
      – Comparison of Key Differences

Key Terms: ABO System, Blood Types, O Negative, O Positive, Plasma, Platelets, Red Blood Cells, Rh Factor, Rh Negative, Rh Positive

What is O Positive

The type O is one of the four blood types found in humans, and it is determined by the presence of the ii alleles in the genome. The O positive blood is determined by the presence of Rh factor on the surface of the O type red blood cells. O positive is the most common blood type among the human population.

Approximately, 38% of the population has O positive blood type. Moreover, O positive blood can be transfused to most blood types such as O positive, A positive, B positive, and AB positive. Thus, O positive blood can be transfused to around 80% of the population. The O positive blood type can receive blood from O positive or O negative blood types. O positive plasma can only be transfused to people with O positive or O negative blood since O positive blood type is determined by the presence of the recessive allele pair (ii). However, anti-A and anti-B antibodies are found in the blood plasma. In the genome, neither A nor B antigens present on the surface of the red blood cells. The O positive platelets can be received by anyone. The ideal donations for O positive blood type are whole blood, double red cells, plasma, and platelets.

Figure 1: Different Blood Types of Humans

Different types of blood in humans based on the ABO and Rh systems are shown in figure 1. 

What is O Negative

The O blood type, which lacks the Rh factor on the surface of the red blood cells is referred to as O negative. Since O negative blood lacks Rh antigen or the antigen D on the red blood cells surface, the D antibody is present in the plasma of the O negative blood. However, O negative blood lacks Anti-A and anti-B antibodies in its plasma. O negative is a rare blood type, which can be identified in 7% of the population. However, O negative blood type is considered as the universal donor since it can be transfused to any type of blood regardless of that persons’ blood type. But, O negative blood type can only receive the same blood type.

Figure 2: Matching Blood Types

The plasma of O negative blood can be transfused to O positive and O negative blood types. The O negative platelets can be received by anyone. The ideal donations for O negative blood type are the whole blood and double red cells. Matching blood types for transfusion are shown in figure 2. 

Similarities Between O Positive and O Negative

• O positive and O negative blood types are determined by the ii allele combination in the genome.

• Both O positive and O negative red blood cells lack anti-A and anti-B antigens on the surface.

• Both O positive and O negative blood can be received by most of the other blood types.

• Both plasma and platelets of O positive and O negative blood types can be received by anyone.

Difference Between O Positive and O Negative

Definition

O Positive: The O blood type that contains the Rh factor/antigen D on the surface of the red blood cells is referred to as O positive.

O Negative: The O blood type that lacks the Rh factor on the surface of the red blood cells is referred to as O negative.

Rh Factor/Antigen

O Positive: Rh factor is present on the surface of the red blood cells of O positive blood.

O Negative: Rh factor is absent on the surface of the red blood cells of O negative blood.

Rh Antibody

O Positive: Rh antibodies cannot be found in the plasma of the O negative blood.

O Negative: Rh antibodies are present in the plasma of the O negative blood.

Anti- A and anti-B Antibodies

O Positive: Anti-A and anti-B antibodies are present in the plasma of O positive blood.

O Negative: Blood plasma lacks anti-A and anti-B antibodies.

Percentage of People

O Positive: Approximately, 38% of the population is O positive.

O Negative: Approximately, 7% of the population is O negative.

Recipients 

O Positive: O positive blood can be transfused to people with O positive, A positive, B positive, and AB positive blood groups.

O Negative: O negative blood can be transfused to all types of blood groups.

Donors

O Positive: O positive blood type can receive blood from O positive and O negative blood types.

O Negative: O negative blood type can only receive blood from O negative blood type.

Ideal Donations

O Positive: The ideal donations for the O positive blood type are whole blood, double red cells, plasma, and platelets.

O Negative: The ideal donations for the O negative blood type are the whole blood and double red cells.  

Conclusion

Humans have four blood types: type A, type B, type AB, and type O. Each of these blood types differ from one another due to the complex chemical substances called blood group antigens present on the surface of the red blood cells. The immune system of the body can recognize these blood group antigens on the red blood cells. If the transfused blood type is different from the existing one, the transfusion reactions may destroy the transfused blood by blood group antibodies. Transfusion reactions can be prevented by blood typing. The ABO system and the presence or absence of the Rh factor are the two methods used to determine the blood type in humans. O positive and O negative are the two types of the blood type O, which is determined by the presence of ii allele combination in the genome of humans. The O positive blood contains the Rh factor on the surface of the red blood cells. But, O negative blood lacks Rh factor on the red blood cell. However, the anti-D antibodies can be found in O negative blood plasma. Therefore, the main difference between O positive and O negative is the presence of Rh factor on the surface of the red blood cells.

Reference:

1. “Blood Types.” NorthShore. N.p., n.d. Web. Available here.  06 Aug. 2017. 
2. “Type O Positive.” Heartland Blood Centers. N.p., n.d. Web. Available here. 06 Aug. 2017.
3. “Type O Negative.” Heartland Blood Centers. N.p., n.d. Web. Available here. 06 Aug. 2017. 

Image Courtesy:

1. “Blood type” by Zappys Technology Solutions (CC BY 2.0) via Flickr
2. “Apangshu Find Blood Group” By Apangshusaha – Own work (CC BY-SA 3.0) via Commons Wikimedia