PRECIPITATION AND AGGLUTINATION

Question 1

• Involves combining soluble antigen with soluble antibody to produce insoluble complexes that are visible.

Answer 1

PRECIPITATION

Question 2

In this method, the detection device is placed directly in line with the incident light, collecting the light that passes directly through the solution.

Answer 2

TURBIDIMETRY

Question 3

Measures the reduction in light intensity caused by reflection, absorption, or scatter as a beam of light passes through a solution.

Answer 3

Turbidimetry

Question 4

The amount of scatter is proportional to the size, shape, and concentration of molecules in the solution and is recorded in absorbance units.

Answer 4

Turbidimetry

Question 5

Instruments that use 🤨 typically measure light scatter at angles ranging from 10 to 90 degrees.

Answer 5

NEPHELOMETRY

Question 6

The amount of light scattered is an index of the solution’s concentration, and this measurement can be used to determine the concentration of an analyte in a solution.

Answer 6

NEPHELOMETRY

Question 7

Measures the light scattered at a particular angle from the incident beam as it passes through a suspension.

Answer 7

NEPHELOMETRY

Question 8

• In this technique, the rate of increase in light scattering is measured immediately after the reagent antibody is added to the patient sample.

When the antibody concentration is kept constant, this rate change is directly related to the antigen concentration in the sample

Answer 8

RATE NEPHELOMETRY

Question 9

MEASUREMENT OF PRECIPITATION BY LIGHT SCATTERING

Answer 9

TURBIDIMETRY
NEPHELOMETRY

Question 10

MEASUREMENT OF PRECIPITATION BY PASSIVE IMMUNODIFFUSION

Answer 10

RADIAL IMMUNODIFFUSION

OUCHTERLONY DOUBLE IMMUNODIFFUSION

Question 11

These techniques detect antigen-antibody reactions based on the diffusion of reactants through a semisolid medium, such as agarose gel, without the aid of an electrical current.

Answer 11

PASSIVE IMMUNODIFFUSION

Question 12

• This single-diffusion technique involves uniformly distributing antibodies within the support gel.
The antigen is then introduced into a well cut into the gel.
• As the antigen diffuses radially from the well, it interacts with the antibodies,
forming a precipitate at the zone of equivalence.
The diameter of this precipitation ring directly correlates with the antigen concentration in the sample.

allows for the quantification of antigen concentrations.

Answer 12

RADIAL IMMUNODIFFUSION

Question 13

• The square of the diameter is directly proportional to the concentration of the antigen.

Answer 13

Mancini method (Endpoint)

Question 14

• The diameter is proportional to the log of the concentration, and a graph is plotted using semi-log paper.

Answer 14

• Fahey method (Kinetic)

Question 15

In this classic technique, both antigen and antibody diffuse independently in two dimensions (horizontally and vertically) through the semisolid medium.

• Wells are cut into the gel, with multi-specific antibodies typically placed in the central well and different antigens loaded into the surrounding wells.

• This setup allows for the comparison of
different antigens and determining if they share identical epitopes.

_____form at the zone of equivalence where the diffusing antigen and antibody fronts meet.

Answer 15

OUCHTERLONY DOUBLE IMMUNODIFFUSION

Precipitin lines

Question 16

• The pattern of these lines reveals the relationship between the tested antigens

Answer 16

OUCHTERLONY DOUBLE IMMUNODIFFUSION

Question 17

•: When the antigens in two wells are identical, the precipitin lines form a
smooth arc, fusing without crossing

Answer 17

Identity

Question 18

: If the antigens are unrelated and share no common epitopes, the precipitin lines cross each other.

Answer 18

• Nonidentity

Question 19

: In cases where antigens share some but not all epitopes, a spur formation is observed, indicating partial cross-reactivity.

Answer 19

• Partial identity

Question 20

Immunoglobulins, comple-ment, C-reactive protein, other serum proteins

Answer 20

Nephelometry

Question 21

Light that is scattered at an angle is mea-sured, indicating the amount of antigen or antibody present.

Answer 21

Nephelometry

Question 22

Immunoglobulins, complement

Antigen diffuses out into gel that is infused with antibody. Measurement of the radius indicates concentration of antigen.

Answer 22

Radial immunodiffusion

Question 23

Both antigen and antibody diffuse out from wells in a gel. Lines of precipitate formed indicate the relationship of antigens.

Complex antigens such as fungal antigens

Answer 23

Ouchterlony double diffusion

Question 24

Electrophoresis of serum followed by diffusion of antibody from wells.

Differentiation of serum proteins

Answer 24

Immunoelectrophoresis

Question 25

Electrophoresis of serum followed by diffusion of antibody from wells. Differentiation of serum proteins

Answer 25

Immunoelectrophoresis

Question 26

Electrophoresis of serum followed by direct application of antibody to the gel. Over-or underproduction of antibody

Answer 26

Immunofixation electrophoresis

Question 27

• This process is a visible expression of the aggregation of antigens and antibodies through forming a framework.

Answer 27

AGGLUTINATION

Question 28

• The process by which particulate antigens, such as red blood cells, aggregate to form larger, visible clumps when the corresponding antibody is present in the serum.

Answer 28

AGGLUTINATION

Question 29

is a two-step process that leads to forming a stable lattice network.

Answer 29

Agglutination

Question 30

AGGLUTINATION • The first step,_______, involves the binding of antigens and antibodies. • This reaction is rapid and reversible. • The second step,______, is the formation of cross-links that make up the visible aggregates. • This step stabilizes the antigen-antibody complexes by binding multiple antigenic determinants together.

Answer 30

sensitization lattice formation

Question 31

is an antigen antibody reaction that occurs when antigens are found naturally on a particle.

Answer 31

Direct agglutination

Question 32

DIRECT AGGLUTINATION • is a specific type of agglutination reaction that uses red blood cells (RBCs) as the indicator particle.

Answer 32

Hemagglutination

Question 33

• Utilize particles coated with antigens not naturally found on their surfaces. • Used to detect antibodies Particles that can be used: erythrocytes, latex, and gelatin.

Answer 33

PASSIVE AGGLUTINATION Also called indirect agglutination

Question 34

Passive agglutination Advantages:

Answer 34

Consistency and uniformity Reactions are easy to read visually and give quick results.

Question 35

Passive agglutination Advantages:

Answer 35

Consistency and uniformity Reactions are easy to read visually and give quick results.

Question 36

Used to detect antigens in a patient sample. In this reaction, it is the antibodies that are attached to the carrier particle. The antibody attached to the carrier particle must still be reactive and bound so that the active sites face outward.

Answer 36

REVERSE PASSIVE AGGLUTINATION

Question 37

This method uses Staphylococcus aureus with Protein A on its surface. Protein A binds to the Fc region of immunoglobulin G (IgG), effectively coating the bacterial cells with the Fc portion of antibodies. When a sample containing the target antigen is added, the antigen binds to the Fab portion of the antibody, resulting in visible agglutination.

Answer 37

COAGGLUTINATION

Question 38

Makes use of some viruses that have receptors for red blood cell (RBC) antigens • Detects antigens

Answer 38

VIRAL HEMAGGLUTINATION

Question 39

VIRAL HEMAGGLUTINATION detects

Answer 39

Antigens

Question 40

A serological technique used to detect the presence of a specific antigen in a patient sample by its ability to inhibit agglutination. Presence of agglutination =______ Absence of agglutination =______

Answer 40

AGGLUTINATION INHIBITION Negative Positive

Question 41

hinges on the ability of certain viruses to bind to receptors on the surface of red blood cells (RBCs), a process known as hemagglutination. • The assay leverages this viral characteristic to determine if a patient possesses antibodies against these hemagglutinating viruses.

Answer 41

• Hemagglutination inhibition

Question 42

The DAT is performed to directly detect in vivo antibody (IgG) or complement coating on RBCs.

Answer 42

COOMB'S TEST DIRECT COOMB'S TEST

Question 43

• IAT detects in vitro antibody (IgG) binding to RBCs.

Answer 43

COOMB'S TEST INDIRECT COOMB'S TEST

Question 44

TYPES OF AGGLUTINATION REACTIONS

Answer 44

DIRECT AGGLUTINATION PASSIVE AGGLUTINATION REVERSE PASSIVE AGGLUTINATION COAGGLUTINATION VIRAL HEMAGGLUTINATION AGGLUTINATION INHIBITION HEMAGGLUTINATION INHIBITION COOMB'S TEST (direct and indirect)

Question 45

TYPES OF AGGLUTINATION REACTIONS

Answer 45

DIRECT AGGLUTINATION PASSIVE AGGLUTINATION REVERSE PASSIVE AGGLUTINATION COAGGLUTINATION VIRAL HEMAGGLUTINATION AGGLUTINATION INHIBITION HEMAGGLUTINATION INHIBITION COOMB'S TEST (direct and indirect)