IS BLOOD TYPING

Question 1

Who Identified the presence of
2 separate erythrocyte Ags (A&B Ags).

Answer 1

Karl Landsteiner (1900)

Question 2

He later proposed 3 separate groups

Answer 2

1. Karl Landsteiner
2. he later proposed 3 groups A, B, & O.

Question 3

Who Identified the 4rth group (AB)

Answer 3

von Decastello & Sturli

Question 4

Amorphic: no detectable Ag is produced
in response to the inheritance of this gene.

Answer 4

Blood type O

Question 5

who discovered 4-allele theory of inheritance?
The 4-allele theory are the ff:

Answer 5

1. Thompson
2. A1,A2,B and O.

Question 6

2 subgroups of A

Answer 6

A1 and A2

Question 7

T or F: H gene is inherited

Answer 7

True

Question 8

H gene codes for the production of _______
that catalyzes the addition of _______ the immunodominant structure of ______ to two slightly different structures known as the _____ and ______

Answer 8

1. α-L- fucosyl transferase
2. L-fucose
3. H antigen
4. type 1 & 2 precursor chains.

Question 9

Expression of H, A, and B Ags:

Gene
H
A
B
O

Answer 9

H- α-L-fucosyltransferase
A- α-3-N-acetyl-D-galactosaminyl transferase
B- α-3-D galactosyl transferase
O- None

Question 10

Classification of the ABO blood
SERUM ANTIBODIES:

A
B
AB
O

Answer 10

A - Anti-B
B - Anti-A
AB - None
O - Anti-A, Anti-B, Anti- A,B

Question 11

RXNS OF PATIENT ERYTHROCYTE & REAGENT ABs

Blood Group:
A
B
AB
O

Answer 11

A : anti A (Positive) Anti B (Negative)
B - Anti A (Negative) Anti B (Positive)
AB - Anti A (Negative) Anti B (Negative)
O - None

Question 12

The major abo genotypes &
phenotypes

Answer 12

PHENOTYPE: A1, A2, A1B, A2B, B, O
GENOTYPE:
A1 - A1/A1, A1/A2, A1/O
A2 - A2/A2, A2/O
A1B - A1/B
A2B - A2/B
B - B/B, B/O
O - O/O

Question 13

The assortment of antigens
actually detectable on an individual’s red
cells using selected antisera. In many blood
group systems, the _______ is an exact
expression of the genotype.

Answer 13

PHENOTYPE

Question 14

The sum of all genes a person has
inherited within a blood group system.

Answer 14

GENOTYPE

Question 15

A series of Ags exhibiting the same serological & physiological characteristics, & inherited according to specific patterns.

Answer 15

BLOOD GROUP SYSTEM

Question 16

Representative ABO frequencies
(Mourant)

A1
A2
B
A1B
A2B
O

Answer 16

A1: W- 32% B-19% O- 27%
A2: W- 9% B-8% O- (Rare)
B: W- 9% B-19% O- 25%
A1B: W- 3% B-3% O- 5%
A2B: W- 1% B-1% O- (Rare)
O: W- 45% B-49% O- 40%

Question 17

Serologic distinction between A1 & A2 Ags is based on the

Answer 17

reactions of erythrocytes w/
various anti-sera.

Question 18

full name of lectin anti-A1

Answer 18

(Dolichos biflorus seeds).

Question 19

Lectin anti-A1 agglutinates in ___ but not in ___

Answer 19

A1, A2 erythrocytes.

Question 20

What are lectins?

Answer 20

Seed extracts that agglutinate human cells
with some degree of specificity.

Question 21

What are some of the lectins? and how and when do they agglutinate?

Answer 21

1. Dolichos biflorus: agglutinates A1 or A1B
2. Bandeiroea simplicifolia: agglutinates B cells
3. Ulex europaeus: agglutinates O cells (H
   specificity) and other ABO blood groups
   depending on the amount of H Ag available.

Question 22

Characteristics of Antisera: Anti-A reagent

Answer 22

Monoclonal Ab
Highly specific
IgM
Clear blue colored reagent
Expected 3+ to 4+ reaction
Usually use 1-2 drops

Question 23

Characteristics of Antisera: Anti-B reagent

Answer 23

Monoclonal Ab
Highly specific
IgM
Clear yellow colored reagent
(contains an acriflavine dye)
Expected 3+ to 4+ reaction
Usually use 1-2 drops

Question 24

Discrepancies in abo forward
grouping (False (+) results)

Answer 24

1.Contaminated reagents or dirty glassware
2. Overcentrifugation
3. Incorrect interpretation or recording of tests results

Question 25

Discrepancies in abo forward
grouping (False (-) results)

Answer 25

1. Lack of specimen or reagents in the test system
2. An incorrect serum: cell ratio
3. Undercentrifugation or incorrect incubation
   temperature
4. Old or otherwise inactive reagents
5. Incorrect interpretation, such as failure to
   recognize hemolysis as a (+) reaction, or an error in
   the recording of test results

Question 26

Other sources of technical errors

Answer 26

1. Inadequate identification of blood specimens, test tubes or slides.
2. Cell suspension either too heavy or too light.
3. Clerical errors
4. A mix-up samples
5. Failure to follow manufacturer’s instructions.
6. Uncalibrated centrifuge

Question 27

IF carefully controlled repeat testing yields the same agglutination patterns, the variation can be assigned to one of 4 categories:

Answer 27

1. Weak or missing antigen reactions
2. Unexpected antigen reactions
3. Weak or missing antibody reactions
4. Unexpected antibody reactions

Question 28

How do you make the cell suspension

Answer 28

3-5% red cell suspension

Question 29

Reporting of Results

Answer 29

Agglutination of RBCs in the presence of
reagent is a positive test result and indicates the presence of the corresponding antigen.

Negative control should have a negative
result; otherwise, further investigation and
testing must be considered.