The key difference between O positive and O negative blood group is that the O positive blood has Rh factor in their red blood cell membranes while the O negative blood does not have Rh factor.
Human blood can be classified into four different types of groups according to the antigen in the cell surface of the red blood cells. In 1900, Landsteiner found two types of antigens; type A and B antigens. So, the surface of red blood cells of a person can have either antigen A or B or neither of them. According to these discoveries, there are four blood groups as A, B, AB, or O.
When deciding the ABO blood system, another important determinant is the antibodies, which is present in the serum of the blood. For example; if the red blood cell surface has the type A antigen, the serum of the blood contains antibodies against type B red blood cells and vice versa. The ABO blood system is inherited through three alleles in chromosome 09 and alleles IA (A), IB (B), and ii (O) are inherited to the second generation from each parent. One parent has only two of these three alleles. Alleles IA and IB are dominant over ii (O).
CONTENTS
1. Overview and Key Difference
2. What is Rhesus Blood Group System
3. What is O Positive Blood
4. What is O Negative Blood
5. Similarities Between O Positive and O Negative Blood Groups
6. Side by Side Comparison – O Positive vs O Negative in Tabular Form
7. Summary
What is Rhesus Blood Group System
Rh (Rhesus) blood group system is an important system that helps to group blood. The presence or absence of the Rh antigen on the cell membrane of the red blood cells determines the positive or negative condition of the blood. Rh gene encodes for the two different antigens C and c, E and e with D, but for the positive or negative condition of the blood type, only D antigen is important. In a transfusion, when Rh positive blood is given to an Rh-negative person, it causes an incompatibility. However, this transfusion is possible for the very first time. Generally, the immune system produces Rh antigens in an Rh-negative person’s body and the next transfusion of Rh-positive blood will cause the destruction of blood cells. Hence, the transfusion of Rh-positive blood to Rh-negative blood is not possible for the second time.
What is O Positive Blood?
Alleles of ii determine the O positive blood type. It lacks the antigens in the red blood cell surface. However, people with O blood group have both anti-A antibodies and anti-B antibodies in the plasma, which act against type A blood and type B blood.
Figure 01: Blood Groups
Usually, an O blood group person can receive blood from an individual who has only O blood group. If the receiver has O positive blood, the donor can be O positive or O negative. O positive individuals can give blood to individuals having A positive, B positive, AB positive, or O positive blood.
What is O Negative Blood?
Same alleles of ii determine the type O negative blood. But it lacks Rh factor and both anti-A antibodies and anti-B antibodies in the plasma. So, type O negative can be given safely to all blood groups, type A positive and negative, B positive and negative, AB negative positive and O negative positive, etc. Hence, we can consider O negative blood group as the universal donor.
But O negative blood group can receive blood only from the same blood group O negative.
What are the Similarities Between O Positive and O Negative Blood Group?
- O Positive and O Negative are two types of blood groups.
- Both blood groups are determined by the same alleles ii.
- Also, both these two blood groups lack anti-A and anti-B antigens on their red blood cell surface.
- Besides, both O positive and O negative blood can be donated to many other blood groups.
What is the Difference Between O Positive and O Negative Blood Group?
The key difference between O positive and O negative is that the O positive blood has Rh factor on their cell membranes of the red blood cells whereas O negative blood does not have Rh factor. Furthermore, type O positive has antibodies; it has both anti-A antibodies and anti-B antibodies in the plasma that act against type A blood and type B blood, whereas O negative blood lacks anti-A and anti-B antibodies in the plasma. Therefore, this is also a significant difference between O positive and O negative.
Moreover, a further difference between O positive and O negative is that the type O positive blood can be given only to persons having A positive, B positive, AB positive, and O positive blood, while O negative person can donate blood to any person. Thus, the type O negative blood is a universal donor whereas O positive is not. So in emergency cases, anyone can be given O negative blood. Also, O positive blood group occupies about 37% of the population while O negative is rare and it is only seen in only 6.6% of the population. Hence, we can consider this too as a difference between O positive and O negative.
The below info-graphic summarizes the difference between O positive and O negative blood group.
Summary – O Positive vs O Negative Blood Group
In summarizing the difference between O positive and O negative blood group, the O positive blood contains Rh factor on the surfaces of red blood cells while the O negative blood lacks Rh factor. Therefore, this is the key difference between O positive and O negative blood group. Furthermore, O negative is a very rare blood group; it occupies only 6.6 % of the population while O positive blood group is common and it occupies 37% of the population. Moreover, O negative is a universal donor, meaning that O negative blood can be transfused to anyone while O positive blood can be donated to people with A positive, B positive, A positive and O positive. Importantly, O positive blood group can receive blood from O positive and O negative while a person with O negative blood can only receive blood by another person with O negative blood.
Reference:
1. “Blood Groups.”NHS Choices, NHS, Available here.
2. “Blood Type.” Wikipedia, Wikimedia Foundation, 23 Feb. 2019, Available here.
Image Courtesy:
1. “Blood Group Chart Designed by ((Sir Ibrahim Awwab)) 29 July 2018” By Sir Ibrahim Awwab – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Blood group O neg 128” By Gilo1969 (talk) (Uploads) – Own work (CC BY 3.0) via Commons Wikimedia