Common Immunohematologic reactions

Question 1

the formation of aggregates of particles that bear antigenic determinants to their surface, which combine with antibodies present in test serum

Answer 1

Agglutination

Question 2

The destruction of red blood cells with subsequent release of Hemoglobin into the surrounding medium

Answer 2

Hemolysis

Question 3

Contents of Negative Control

Answer 3

3% RCS with 2 drops of NSS

Question 4

Contents of Positive Control for Hemolysis

Answer 4

5% RCS with 2 drops of distilled water

Question 5

Contents of Test A

Answer 5

3% RCS with undiluted anti-D sera

Question 6

Contents of Test B

Answer 6

3% RCS with diluted anti-D sera

Question 7

Test C Contents

Answer 7

5% RCS with undiluted anti-D sera

Question 8

Test D contents

Answer 8

5% RCS with diluted anti-D sera

Question 9

One solid aggregates

Answer 9

4+

Question 10

Several alrge agglutinates

Answer 10

3+

Question 11

Medium-sized agglutinates, clear background

Answer 11

2+

Question 12

Small agglutinates, turbid background

Answer 12

+1

Question 13

Barely visible agglutination, turbid background

Answer 13

W or +/-

Question 14

stages of agglutination reaction

Answer 14

Sensitization

Lattice Formation

Question 15

stage where antigen binds to the antibody/antigen-antibody combination

Answer 15

Sensitization

Question 16

Its structure is composed of multiple antigen-antibody bridges between RBC antigens and antibodies is formed

Answer 16

Lattice formation

Question 17

effect if centrifugation to Ag-Ab reaction

Answer 17

it decreases reaction time by increasing the graviational forces in the reactants and bringing reactants closer together

Question 18

Factors that influence Agglutination Reaction

Answer 18

1) Centrifugation
2) Antigen-Antibody Ratio
3) pH
4) Temperature
5) Immunoglobulin type
6) Protein Media
7) Low Ionic Strength Solutions (LISS)

Question 19

excess of unbound Ig (Ab)

Answer 19

prozone effect

Question 20

surplus of antigen

Answer 20

postzone effect

Question 21

solution for prozone effect

Answer 21

plasma or serum may be diluted with appropriate buffer

Question 22

solution for postzone effect

Answer 22

increase serum-to-cell ratio which tends to increase no. of Ab available to bind with each RBC

Question 23

result of absent lattice formation

Answer 23

false negative results

Question 24

ideal pH for Ag-Ab reaction

Answer 24

6.5-7.5

Question 25

antibodies usually react aptimally at ambient temperatures orbelow 22 Degree Celsius at immediate spin phase of testing

Answer 25

IgM

Question 26

antibodies that usually require 37 Deg Celsius incubation and react optimally at the antihan globulin (AHG) phase of testing

Answer 26

IgG

Question 27

Two common products of antigen-antibody/immunohematologic reactions

Answer 27

agglutination and hemolysis

Question 28

capsble of agglutinating RBCs suspended in a 0.85% to 0.90% saline medium

Answer 28

IgM

Question 29

work by increasing the dielectric constant, which then reduces the zeta pitential of the RBC

Answer 29

Colloids

Question 30

examples of colloids

Answer 30

albumin, polyethylene glycol, polybrene, plyvinylpyrrolidone and protamine.

Question 31

macromolecule additives used with LISS to being sensitized RBCs closer to each other to facilitate antibody cross-linking and agglutination reactions

Answer 31

Polyethylene glycol and polybrene