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Blood group and Rh factor

1. What is blood Grouping? Why the determination of blood group is important?

Ans.  Agglutination of blood cells depends on the reaction of Agglutinogen and Agglutinin present in the blood. Grouping of human blood can on the basis of the Agglutinogen and Agglutinin into different of categories is known as blood group. It is important in: (i) Detection of blood, Diseases, (ii) Paternity test, (iii) Forensic purposes, (iv) Phylogenetic and Anthropological research.

2. What is ABO system?

Ans. Agglutination depends on the reaction between Agglutinogen in RBC and Agglutinin present in plasma. Although many kinds of agglutinogens are associated with RBC, for blood transfusion therapy, A and B agglutinogens are most important. The distribution of these and the antigens and their respective antibodies in human beings is known as ABO system.

3. How can you classify human blood on the basis of ABO system?

Ans. Human blood may be grouped on the basis of ABO system in the following way:

Agglutinogen present  (in RBC)

Agglutinin present (in serum)

Blood group

A

beta

A

B

alpha

B

A & B

None

AB

None

alpha, beta

O

4. What is agglutination?

Ans. Agglutinogen (in RBC) reacts with Anti-Agglutinin (in Plasma) to clump and ultimately to destroy the RBC: This reaction is called agglutination. In fact, ? antibody (Agglutinin) is unsuitable for A antigen (Agglutinogen). So a mixture of the bloods containing these two would result is agglutination.

5. Who discovered ABO system? What is Antigen-Antibody reaction?

Ans. ABO system was discovered by Landstreiner (1901). The antigen-antibody reaction means the interaction between the Agglutinogen present in the RBC and Agglutinin present in the serum. Human beings contain A and B Agglutinogen (Antigen) and ? and ? Agglutinins (Antibody). A antigen reacts with ?  antibody to agglutinate the blood and vice-versa.

6. How can you determine the group of a blood sample?

Ans. Blood group may be determined with the aid of antiserums containing ? and ? agglutinin in the following way:

i) Blood diluted in 0.9 % NaCl solution is taken in two slide: one drop each.

ii) In first slide one drop of Antiserum-A (?-agglutinin), while in the second Antiserum-B ( ?-agglutinin) is added and observed for agglutination.

iii)

Agglutination with

Group

Anti-A

A

Anti- B

B

Anti-A and B both

AB

No agglutination

O

7. What is Rh Factor?

Ans. Rh Factor is an Agglutinogen, discovered originally from Rhesus Macaque. It is also present in the RBC of man. Although no Agglutinin for it is found. Although Rh system includes 8 different Rh Factors, the Factor D is most important. It may cause severe effects in man.

8. How can you designate the blood group indicating both the ABO and Rhesus systems?

Ans. As Rhesus Factor containing blood is designated as Rh+ (Rhesus, Positive) and blood lacking it as Rh- (Rhesus, Negative), both ABO and Rh systems can be designated as follow:

i) Blood groups with Rh Factor: A+, B+, AB+ and O+

ii) Blood groups without Rh Factor: A-, B-, AB- and O-.

9. What is the importance of Rh system?

Ans. i) Rh- persons produce D antibody when they are expressed to D antigen. If they are transfused Rh+ blood a severe reaction is likely to occur.

ii) Development of Rh+ foetus within the womb of Rh- mother may result in abortion or birth of baby with severe anaemia, Erythroblastosis or Jaundice.

10 What do you mean by Universal Donor?

Ans. A universal Donor is a person whose blood contains both ? and ? antibodies but no antigen. Thus, his blood belongs to the group O and can be transfused to any person with any of the ABO groups. O and can be transfused to any person with any of the ABO groups.

11. What do you mean by Universal Recipient?

Ans. A Universal Recipient is a person whose blood contains both A and B antigens, but no antibody, thus, his blood belongs to Group AB and he can receive the blood of any person with any of the ABO groups.

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This entry was posted on Thursday, April 16th, 2009 at 5:57 pm and is filed under General Zoology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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