IMSE311 (LEC) - FINALS: BASIC IMMUNOLOGIC PROCEDURES

A medical science dealing with blood serum especially in regard to its immunological reactions and properties.

Serology

TRUE OR FALSE

Yellow tops may be used in serological tests.

FALSE

If a blood is delayed for less than 72 hours, what should be done to preserve the specimen?

Refrigerate it

If a blood is delayed for more than 72 hours, what should be done to preserve the specimen?

Freeze at -72°C

TRUE OR FALSE

In preparing the specimen for serological tests, whole blood can be refrigerated.

FALSE - only the serum can be refrigerated.

This refers to preparation of blood specimen by transferring the serum into a compatible secondary container.

Aliquot

Name at least 3 agents for erroneous results

1. Icteric Sample

2. Turbid Samples

3. Bacterial Contamination

4. Chyle

5. Contamination with alkali or acid

6. Incorrect time of collection

If the serum is highly turbid and testing is necessary, troubleshooting should be performed by ______ the lipids to minimize analytical interference.

Precipitating

Considered as the process that destroys complement activity.

Inactivation

known to interfere with the reactions of certain syphilis tests

Complement

In Latex Passive Agglutination Assays, complement activation may interfere by producin a ________ result

A. False Positive

B. False Negative

A.

In Hemagglutination Assays, complement activation may interfere by producin a ________ result

A. False Positive

B. False Negative

B.

How is complement inactivated?

By heating it to 56ºC for 30 minutes

How is complement reinactivated?

By heating it to 56ºC for 10 minutes after more than 4 hours since activation

What are the types of agglutination reaction?

1. Direct

2. Indirect

3. Reverse passive

4. Agglutination inhibition

5. Coaggulatination

The process whereby specific antigens (e.g., red blood cells) aggregate to form larger visible clumps.

Agglutination

Antibodies that induce agglutination reaction are often called ______

Agglutinins

Warm-reacting antibody

A. IgG

B. IgM

A

Give particles that can initiate agglutination

1. Erythrocytes

2. Bacterial Cells

3. Inert Carriers such as latex particles

The first step in agglutination, where involves antigen – antibody combination through single antigenic determinants on the particle surface

Sensitization

TRUE OR FALSE

Sensitization is rapid and reversible

TRUE

A step in agglutination considered as the sum of interactions between antibody and multiple antigenic determinants on a particle.

Lattice Formation

In agglutination, this occurs when multiple antibodies bind to different

epitopes on the antigen

Lattice Formation

A type of agglutination that Occurs when antigens are found naturally on a particle.

Direct Agglutination

It is an agglutination reaction involves red blood cells/erythrocytes which

contains antigens that are naturally attached to it.

Hemagglutination

A serum specimen was sent for RF Latex Agglutination. The medical technologist processed it. Upon adding the anti-sera, the medical technologist waited for few seconds. A smooth milky suspension was seen. What is the result?

NEGATIVE for RF

A type of agglutination reaction which employs particles that are coated with antigens not normally found on their surfaces.

Passive or Indirect Agglutination

Particles which Are inexpensive, are relatively stable, and are not subject to cross-reactivity with other antibodies.

Latex Particles

In indirect agglutination assays, these serve as ccariers for the antigen

Latex particles

Immunoglobulin which is capable of adsorption when added to the surface of polystyrene latex particles.

IgG

In this type of agglutination reaction, antibody rather than antigen is

attached to a carrier particle

Reverse Passive Agglutination

With any agglutination reactions, patients with a positive _______ may cause a false positive results as it reacts with any IgG antibody.

Rheumatoid Factor

In reverse passive agglutination, which is coated in the latex particles?

Antibodies

Which type of agglutination reaction is depicted in the image?

Passive/Indirect agglutination since carrier particle is coated with a soluble antigen.

Which type of agglutination reaction is depicted in the immage?

Reverse Passive Agglutination since antibodies coat the coated particles, as seen in the image.

This type of agglutination reaction is based on competition between particulate and soluble antigens for limited antibody-combining sites

Agglutination Inhibitions

What is the positive indication of an agglutination inihibition reaction?

A. Presence of agglutination

B. Lack of agglutination

B

MODIFIED TRUE OR FALSE:

1. In agglutination inhibition reaction, the positive indicator of reaction is the lack of agglutination.

2. Particulate antigens are small and monovalent. Hence, when added to the sample along with the antibody reagent, no visible lattice formation occurs.

A. Statement 1 is true

B. Statement 2 is true

C. Both statements are true

D. Both statements are false

A

Which agglutination reaction is depicted in the photo?

Agglutination Inhibition Reaction

A type of hemagglutination inhibition reaction, which uses erythrocytes as indicator particles.

Hemagglutination Inhibition

In coagglutination reaction, which is used as the inert particle wherein antibody is attached to?

Bacteria

This is the most commonly used bacteria in coagglutination reactions

Staphylococcus aureus

used to demonstrate in vivo attachment of antibody or complement

to an individual’s red blood cells.

Direct Antiglobulin Test

A type of AHG which can serve as an indicator of AHA, HDN and determine the sensitization of erythrocytes during transfusion reactions.

Direct Antiglobulin Test (DAT)

This is used to determine the presence of a particular antibody in a patient,

or it can be used to type patient red blood cells for specific blood group

antigens.

Indirect Antiglobulin Test

Determine whether it can cause false positive or false negative reactions in agglutination test

1. Overcentrifugation

2. Contaminated glassware, slides or reagents

3. Inactive reagents

4. Improper washing of cells

5. Incorrect incubation time

6. Cross-reactivity

7. Saline stored in glass bottles

8. Postzone phenomenon

9. Failure to add antiglobulin reagent

10. Delays in testing procedures

11. Delays in reading the slides

12. Heterophile antibody

13. Autoagglutination

14. Undercentrifugation

15. Rheumatoid Factor present in patient’s sample

1. FALSE POSITIVE

2. FALSE POSITIVE

3. FALSE NEGATIVE

4. FALSE NEGATIVE

5. FALSE NEGATIVE

6. FALSE POSITIVE

7. FALSE POSITIVE

8. FALSE NEGATIVE

9. FALSE NEGATIVE

10. FALSE NEGATIVE

11. FALSE POSITIVE

12. FALSE POSITIVE

13. FALSE POSITIVE

14. FALSE NEGATIVE

15. FALSE POSITIVE

involves combining soluble antigen with soluble antibody to produce Insoluble complexes that are visible.

Precipitation

Step in precipitation where first bidning to epitope occurs

A. Avidity

B. Affinity

C. Sensitization

D. Lattice Formation

B.

Is the initial force of attraction that exists between a single Fab site on an antibody molecule and a single epitope

Affinity

In precipitation reactions, this represents the sum of all the attractive forces between an antigen and an antibody.

Avidity

Area where optimum precipitation or agglutination occurs.

Zone of Equivalence

This is where the antibody is excessive, in which antigen combines with only one or two antibody molecules.

Prozone

TRUE OR FALSE

Lattice Formation and Avidity may be achieved with postzone phenomenon. However, sensitization and affinity will occur since antibodies only affect lattice formation and avidity.

A. Statement 1 is true

B. Statement 2 is true

C. Both Statements are true

D. Both statements are false

B.

A serological technique wherein reactants are added to the gel.

Passive Immunodiffusion

Term used to coin as the migration of concentrated solution to a less concentrated solution.

Diffusion

A type of passive immunodiffusion that measures the size of the radius/clear zone.

Radial Immunodiffusion

TRUE OR FALSE

In radial immunodiffusion, the larger the radius of the precipitin ring, the higher the antigen concentration

TRUE

A type of radial immunodiffusion which measures the radius of the precipitin ring at the endpoint, which is when antigen-antibody reaction is complete and the ring stops growing.

Mancin / Endpoint Method

A type of radial immunodiffusion that It measures the radius of the precipitin ring at intervals before reaching the endpoint.

Fahley-McKelvey Method/ Kinetic Method

In Ouchterlony double diffusion, these are measured to observe the reaction between antigen and antibody.

Ouchterlony Double Diffusion

Presence of lines that merge into a curved precipitin line is known as ____

A. Complete identity

B. Partial identity

C. Non-identity

B.

Presence of spur that form between the lines is known as ____

A. Complete identity

B. Partial identity

C. Non-identity

B.

Lines that remain straight and does not form a precipitate is known as ____

A. Complete identity

B. Partial identity

C. Non-identity

C.

A technique that separates molecules according to differences in their electric charge when they are placed in an electric field.

Electrophoresis

This is a double diffusion technique that incorporates electrophoresis current to enhance results/ speed up the separation.

Immunoelectrophoresis

What is the end result of a rocket immunoelectrophoresis?

precipitin line that is conical in shape

A type of electrophoresis, wherein antiserum is applied directly to the gel’s surface after electrophoresis takes place,

Immunofixation Electrophoresis

What is the postive result of a complement fixation test?

A. Presence of Agglutination

B. Presence of Hemolysis

C. No Hemolysis occurs

D. No Agglutination occurs

C.

What is the negative result of a complement fixation test?

A. Presence of Agglutination

B. Presence of Hemolysis

C. No Hemolysis occurs

D. No Agglutination occurs

B.

The formation of downy masses of precipitate that occurs over a narrow

range of antigen concentration.

Flocculation

What is the reagent used in flocculation to form flocs or clumps.

Charcoal