Last Updated on May 27, 2017

Frequently Asked Questions

1. Are there any other blood types besides the ABO blood group?

There are many other types of antigens which may occur on the surface of red blood cells. However, most of them are classified as "minor" and are not as important as ABO and rhesus. They are the Duffy, Kell, Kidd, MNS, and P systems. Tests for antigens from these systems are not included in routine blood typing.

2. Are there subtypes of blood group A?

There are about 20 different subgroups of blood group A of which A1 and A2 subtypes are the most common.

3. Why is blood group O negative considered the universal donor?

A person having O negative blood group lacks all the antigens and hence has antibodies against A and B antigens in their plasma. Hence they can donate blood to people with any blood group.

4. Is there a criteria for blood donation?

The American Red Cross association has certain rules for donating blood. One is the person must weigh at least 110 lbs. Also, if they are 18 years or younger they must meet additional height and weight criteria for whole blood donation.

5. What is Apheresis?

In apheresis, blood is circulated through an apparatus in order to remove only a particular component; the remaining blood is put back into circulation.

6. What are the conditions for blood storage?

Frozen red cells are stored at - 85 0F up to 10 years whereas less-dense blood plasma is split into components and each of them are stored according to different criteria.

7. When can you not donate blood?

You cannot donate blood if you -
  • Are HIV positive
  • Are a Hepatitis B or C carrier
  • Have received money or drugs for sex
  • Have taken injections with drugs, body-building drugs or injectable tanning agents.

8. What is the Bombay blood group?

When somebody lacks the basic H antigen on their red blood cells, they are known to have a Bombay blood group. Hence, these individuals also lack A and B antigens since the H antigen is their precursor. Their plasma develops antibodies towards the H antigen as well as antigens A and B. Hence they can only receive blood from people who have the Bombay blood group.

9. Can the parent and the fetus have different Rh factors?

Yes. The mother may be Rh negative but the baby could be Rh positive if it inherits the D antigen from the father.

10. Is Rh incompatibility between mother and fetus serious?

If the mother is Rh negative meaning she does not have the Rh factor and she bears a child who is Rh positive, that is having the Rh factor, the mother’s blood will develop antibodies against the fetal RBCs. These small antibodies can cross the placenta and cause hemolysis of the baby’s RBCs. The baby can develop a hemolytic disease characterized by low fetal red blood cell count.


gayatri27 Thursday, April 10, 2014

My mother blood group B and my father is A then my blood group is O HOW IS POSSIBLE?

@Guest Thursday, May 15, 2014

It seems "A" can be genetically AO, and "B" can be BO, such that the offspring, which gets one letter from each parent, can be OO.

jensen Tuesday, December 31, 2013

My father -o grp my mother _b grp am I possible ab group have check various many possible ans please verify thks

raghav721 Friday, March 22, 2013

My Mom and Dad are A blood group. But I am A-ve! Is it possible ?

asia31 Friday, September 28, 2012

Hi im a 32 year old black make and I have type A2 blood type can someone explain to me about that blood type..

Rlodha Sunday, September 16, 2012

I wish to know the procedure or the process of testng the Blood Group

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