[M] Lec 02.2: Intro to Sero (Terminologies)

Question 1

Refers to:

• Laboratory study of the activities of the components of blood serum, the antigens and antibodies, that contributes to immunity.
• The in vitro study of antigen-antibody reaction. These reactions can be classified into three which are primary, secondary, and tertiary reactions.

Answer 1

Serology

Question 2

Terminologies

1. The ability of a test to generate true negative results.
2. The ability of a test to generate true positive results.
3. Associated with polyclonal antibodies as it is the ability to react with multiple epitopes.
4. Associated with monoclonal antibodies as it is the ability to react with single epitope.

Answer 2

1. Specificity
2. Sensitivity
3. Avidity
4. Affinity

Question 3

Terminologies

5. Defined as the reciprocal of the HIGHEST DILUTION and LOWEST CONCENTRATION that shows positive result.
6. Occurs when different organisms share the same antigen.
7. The test should be in the zone of equivalence in order to visualize the precipitation or agglutination reaction.
8. The second stage of agglutination, next to the sensitization phase

Answer 3

5. Titer
6. Cross reactivity
7. Zonal reactions
8. Immune complexes or lattice formation

Question 4

T or F:

• If a test has increased specificity, it is an indication that the est has an increased true positive results.
• In contrast, if a test is not sensitive, or a test has a decreased sensitivity, it is an indication that the test has an increased false negative results

Answer 4

False (First statement should be increased SENSITIVITY*)

Question 5

This is the characteristic of screening tests

Answer 5

Sensivity

Question 6

Characteristic of confirmatory tests

Answer 6

Specificity

Question 7

Refers to:

• Force of attraction between an antigen and an antibody.
• A characteristic of IgG since it is a monomer antibody

Answer 7

Affinity

Question 8

Strength of interaction between complex antigens

Answer 8

Avidity

Question 9

1. Characteristic of IgM
2. Characteristic of IgG

Answer 9

1. Avidity
2. Affinity

Question 10

Match

1. Increased avidity and sensitivity; decreased affinity
2. Increased affinity and specificity; decreased avidity
3. Increased avidity and sensitivity; decreased avidity
4. Can only react to a single epitope of an antigen
5. Can react to multiple epitopes of an antigen

A. Polycloncal antibodies
B. Monoclonal antibodies
C. Walang ganun

Answer 10

1. A
2. B
3. C
4. B
5. A

Question 11

Refers to:

• First, the antigen is injected into rabbits. Once injected, just like in humans, whenever foreign antigens are introduced, it will induce the production of antibodies.
• The B cells of the rabbits will be activated, becoming plasma cells.
• The plasma B cells produce antibodies. These antibodies will then be collected from the serum of the rabbits which will be used as the reagent for testing.

Answer 11

Polyclonal antibodies

Question 12

Refers to:

• It makes use of the hybridoma technology. Instead of rabbits, it uses mice or rats as hosts. These animals are injected with the target antigen and will produce antibodies
  against the antigen.
• The activated B cells or plasma cells of the mouse will be combined with tumor or myeloma cells leading to the creation of hybrid cells known as hybridomas, hence hybridoma technology.
• The fusion results in the creation of hybridomas and these ells are cultured to multiply and screened to identify those that produced the desired antibodies

Answer 12

Monoclonal antibodies

Question 15

Refers to:

The sensitized particulate molecules that will crosslink to form visible reactions

Answer 15

Lattice formation

Question 16

With this, tests will have decreased specificity leading to false positive results

Answer 16

Cross reactivity

Question 16

Familiarize the uses and application of serology

Answer 16

a. Diagnosis of Infectious Diseases
b. Diagnosis of Immunological Abnormalities
c. Immunoassay of hormones
d. Serotyping or Serologic ID of microorganisms
e. Forensic Medicine
f. Phylogenic Classification

Question 17

Answer whether the ff items will cause a false positive or a false negative

1. Bacterial contamination
2. Hemolysis
3. Improper time & temp. of incubation
4. Too early infection
5. Omit reagent / serum
6. Delay in reading
7. Cross reaction - Antigen sharing
8. Prozone and postzone

Answer 17

1. FP
2. FP
3. FN
4. FN
5. FN
6. FP
7. FP
8. FN

Question 18

Clinical speciments that are most commonly used in serological testing

Answer 18

Serum, CSF, Plasma, Urine, Tissue/biopsy

Question 19

Diagnostic serology

1. Incubation temperature
2. Days interval between acute and convalescent serum
3. Short term storage for preservation of serum
4. Long term storage for preservation of serun
5. Physical inactivation of serum
6. Chemical inactivation of serum
7. Chemical preservation of serum

Answer 19

1. 37°C for 15 to 30 minutes
2. 7-14
3. 4-6°C
4. -20°C
5. Heating the serum at 56°C for 30 minutes or 60-62°C for 3-4 minutes.
6. Choline chloride
7. 0.001g Merthiolate powder/ml of serum
   or 5% phenol or tricresol at 0.1 ml/ml of
   serum

Question 20

This allows antigen-antibody reaction, to catalyze enzymatic reaction, and to activate the
enzymes.

Answer 20

Incubation period

Question 21

Diagnostic serology

1. This is performed in order to determine if the titer of the patient has increased during the infection
2. What is considered a significant titer from the normal value?

Answer 21

1. Interval between acute and convalescent serum
2. 4-fold increase

Question 22

Samples

1. Diagnosis of Neurosyphilis
2. Measure metabolits of hormones
3. Detect ERPR

Answer 22

1. CSF
2. Urine
3. Tissue/Biopsy

Question 23

Screening test for syphilis

Answer 23

Venereal Disease Research Laboratory Test

Question 24

T or F: Paired sera is useful to determine the phase of infection, but this is not being performed nowadays, as there are other more specific tests for the diagnosis of infections

Answer 24

True

Question 25

Two ways how complement is inactivated

Answer 25

1. Physical 2. Chemical

Question 26

If the testing was delayed for more than 4-6 hours, we need to __________ the complement using heat at 56oC for 10 minutes.

Answer 26

Reactivate

Question 27

1. Sample needed for reactivation 2. Sample not needed for inactivation A. Serum B. CSF

Answer 27

1. A 2. B

Question 28

Once cells are lysed, it may lead to false (positive/negative) reactions

Answer 28

False Positive

Question 29

1. Preferred vacutainer in serology 2. Preferred vacutainer in chemistry

Answer 29

1. Plain red top 2. Gold top

Question 30

T or F: We need to first separate the serum to the RBCs. If we fail to separate, cells may lyse leading to false negative results

Answer 30

False (False positive results)

Question 31

T or F: Serology is a routine test

Answer 31

False

Question 32

T or F: Chemical preservation is not usually done and not commonly used

Answer 32

True

Question 33

Classifications of serological tests

Answer 33

Primary, secondary, or tertiary Ag-Ab

Question 34

Classify the ff serological tests 1. It is the combination of Ag and Ab, leading to a NON-VISIBLE REACTION, unless we use equipment. 2. It is an immunologic reaction that OCCURS IN VIVO—in vivo meaning inside the body. * It is a biologic reaction. 3. It is a demonstrable Ag and Ab reaction, leading to a VISIBLE REACTION.

Answer 34

1. Primary 2. Tertiary 3. Secondary

Question 35

Classify serological tests o Farr Technique o Equilibrium Dialysis o Labeled Immunoassay (Ligand Immunoassay; e.g. EIA)

Answer 35

Primary

Question 36

Classify serological tests o Precipitation o Agglutination o Complement Fixation o In Vitro Neutralization

Answer 36

Secondary

Question 37

Classify serological tests * Test for Phagocytosis * Index of Phagocytosis * Test for Opsonization * Test for Chemotaxis * Skin Test * In Vivo Neutralization

Answer 37

Tertiary