S1 [LAB]: Exp 3: Hemagglutination; Exp 4: Hemolysis Flashcards
Used to identify and distinguish a number of substances such as foreign agents or pathogens
Antibodies
Two of the most common endpoints used in the laboratory detection of antigen-antibody reactions in vitro
Aggregation of cells
Hemolysis
Refers to the clumping of particles caused by the union of specific antibody molecules with particulate antigens expressed on a cell surface
Agglutination
Type of agglutination:
The formation of clumps of cells or inert particles by specific antibodies to surface antigenic compounds
Direct
Type of agglutination:
The formation of clumps of cells or inert particles to antigenic components adsorbed or chemically coupled to red cells or inert paticles
Passive
Type of agglutination:
Involve attaching an antigen to a particle of some sort (latex beads, tanned red blood cells) and then running an agglutination reaction with antibody
Passive
Give the red cell button grade after centrifugation:
One solid clump
4+
Give the red cell button grade after centrifugation:
Several large clumps with clear supernatant
3+
Give the red cell button grade after centrifugation:
Numerous smaller clumps in light red supernatant
2+
Give the red cell button grade after centrifugation:
Barely discernable clumps; several small clumps of cells with turbid reddish supernatant
1+
Give the red cell button grade after centrifugation:
Smooth suspension
Negative
Interpret the agglutination result:
Large clumps and clear background
Strong agglutination
Interpret the agglutination result:
Small clumps and cloudy background
Weak agglutination
Interpret the agglutination result:
Even suspension and cloudy background
Negative
Specimen for hemagglutination experiment
Cell-serum mixture
Give the red cell button grade after centrifugation:
Any degree of agglutination in a sea of unagglutinated cells
MF (mixed field)
Refers to red cells that pile up like stacks of coins
Rouleaux formation
T/F: Rouleaux formation may be observed if serum is used instead of plasma
False (rouleaux is often caused by plasma, not serum)
Distinguishing a true agglutination from rouleaux formation is aided by what reagent?
Normal saline solution
The reciprocal of the maximum dilution that gives visible agglutination
Titer
The well with the lowest concentration of the antibodies in which there is agglutination
Endpoint
Give the agglutination reaction grading in the microtiter plate method:
Uniform mat covering the entire wall
4+
Give the agglutination reaction grading in the microtiter plate method:
Uniform mat covering most of the well
3+
Give the agglutination reaction grading in the microtiter plate method:
Less mat covering the well surrounded by a light ring
2+
Give the agglutination reaction grading in the microtiter plate method:
Mat not covering most of the well surrounded by a denser ring
1+
Give the agglutination reaction grading in the microtiter plate method:
Dense ring with hazy edge and shadow
+/-
The rupturing or destruction of red blood cells resulting from the interaction of antibody-coated RBCs with several serum factors of the complement system
Hemolysis
Inactivation of serum is done at what temperature?
56C (30 mins)
60-62C (2-3 mins)
Interpret the hemolysis reaction:
Clear or light yellow of the supernatant with an intact cell button
Negative
Interpret the hemolysis reaction:
Pinkish to light red color of the supernatant with the presence of a cell button
Partial hemolysis
Interpret the hemolysis reaction:
Bright red color of the supernatant with no cell button
Complete hemolysis
In the microscopic observation of weak reaction, this objective scans for areas for a good spread or distribution of red cells
LPO
In the microscopic observation of weak reaction, this is where possible cells in clumps or aggregates are observed
HPO
