Blood groups and blood typing

Question 1

What is Landsteiner’s law?

Answer 1

If an agglutinogen (antigen) is present on red blood cell membrane, the corresponding agglutinin (antibody) must be absent in the plasma.

If an agglutinogen is absent on red blood cell membrane, the corresponsing agglutinin must be present in the plasma.

Question 2

Which antigens (agglutinogens) are present in the red blood cells of people and which antibodies (agglutinins) are in the blood of people with blood types:

A
B
AB
O

Answer 2

Blood group A: A antigen, Anti-B antibody

Blood group B: B antigen, anti-A antibody

Blood group AB: A and B antigens, no antibodies

Blood group O: No antigens, anti-A and anti-B antibodies

Question 3

Describe the structure of agglutinogens

Answer 3

Carbohydrates (oligosaccharides)

Question 4

A and B are mainly what type of antibody?

Answer 4

Mainly IgM with smaller quantities of IgG

Question 5

Why are ABO antibodies capable of causing intravascular haemolysis?

Answer 5

Activate complement at 37ºC

Question 6

Where is the ABO locus found?

Which are dominant and which are recessive?

Answer 6

Chromosome 9

A and B alleles are co-dominant

O allele is recessive