[M] Lec 02.2: Intro to Sero (Terminologies) Flashcards
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.
Serology
Terminologies
- The ability of a test to generate true negative results.
- The ability of a test to generate true positive results.
- Associated with polyclonal antibodies as it is the ability to react with multiple epitopes.
- Associated with monoclonal antibodies as it is the ability to react with single epitope.
- Specificity
- Sensitivity
- Avidity
- Affinity
Terminologies
- Defined as the reciprocal of the HIGHEST DILUTION and LOWEST CONCENTRATION that shows positive result.
- Occurs when different organisms share the same antigen.
- The test should be in the zone of equivalence in order to visualize the precipitation or agglutination reaction.
- The second stage of agglutination, next to the sensitization phase
- Titer
- Cross reactivity
- Zonal reactions
- Immune complexes or lattice formation
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
False (First statement should be increased SENSITIVITY*)
This is the characteristic of screening tests
Sensivity
Characteristic of confirmatory tests
Specificity
Refers to:
- Force of attraction between an antigen and an antibody.
- A characteristic of IgG since it is a monomer antibody
Affinity
Strength of interaction between complex antigens
Avidity
- Characteristic of IgM
- Characteristic of IgG
- Avidity
- Affinity
Match
- Increased avidity and sensitivity; decreased affinity
- Increased affinity and specificity; decreased avidity
- Increased avidity and sensitivity; decreased avidity
- Can only react to a single epitope of an antigen
- Can react to multiple epitopes of an antigen
A. Polycloncal antibodies
B. Monoclonal antibodies
C. Walang ganun
- A
- B
- C
- B
- A
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.
Polyclonal antibodies
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
Monoclonal antibodies
Refers to:
The sensitized particulate molecules that will crosslink to form visible reactions
Lattice formation
With this, tests will have decreased specificity leading to false positive results
Cross reactivity
Familiarize the uses and application of serology
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
Answer whether the ff items will cause a false positive or a false negative
- Bacterial contamination
- Hemolysis
- Improper time & temp. of incubation
- Too early infection
- Omit reagent / serum
- Delay in reading
- Cross reaction - Antigen sharing
- Prozone and postzone
- FP
- FP
- FN
- FN
- FN
- FP
- FP
- FN
Clinical speciments that are most commonly used in serological testing
Serum, CSF, Plasma, Urine, Tissue/biopsy
Diagnostic serology
- Incubation temperature
- Days interval between acute and convalescent serum
- Short term storage for preservation of serum
- Long term storage for preservation of serun
- Physical inactivation of serum
- Chemical inactivation of serum
- Chemical preservation of serum
- 37°C for 15 to 30 minutes
- 7-14
- 4-6°C
- -20°C
- Heating the serum at 56°C for 30 minutes or 60-62°C for 3-4 minutes.
- Choline chloride
- 0.001g Merthiolate powder/ml of serum
or 5% phenol or tricresol at 0.1 ml/ml of
serum
This allows antigen-antibody reaction, to catalyze enzymatic reaction, and to activate the
enzymes.
Incubation period
Diagnostic serology
- This is performed in order to determine if the titer of the patient has increased during the infection
- What is considered a significant titer from the normal value?
- Interval between acute and convalescent serum
- 4-fold increase
Samples
- Diagnosis of Neurosyphilis
- Measure metabolits of hormones
- Detect ERPR
- CSF
- Urine
- Tissue/Biopsy
Screening test for syphilis
Venereal Disease Research Laboratory Test
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
True
Two ways how complement is inactivated
- Physical
- Chemical
If the testing was delayed for more than 4-6 hours, we need to __________ the complement using heat at 56oC for 10 minutes.
Reactivate
- Sample needed for reactivation
- Sample not needed for inactivation
A. Serum
B. CSF
- A
- B
Once cells are lysed, it may lead to false (positive/negative) reactions
False Positive
- Preferred vacutainer in serology
- Preferred vacutainer in chemistry
- Plain red top
- Gold top
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
False (False positive results)
T or F: Serology is a routine test
False
T or F: Chemical preservation is not usually done and not commonly used
True
Classifications of serological tests
Primary, secondary, or tertiary Ag-Ab
Classify the ff serological tests
- It is the combination of Ag and Ab, leading to a NON-VISIBLE REACTION, unless we use equipment.
- It is an immunologic reaction that OCCURS IN VIVO—in vivo meaning inside the body.
* It is a biologic reaction. - It is a demonstrable Ag and Ab reaction, leading to a VISIBLE REACTION.
- Primary
- Tertiary
- Secondary
Classify serological tests
o Farr Technique
o Equilibrium Dialysis
o Labeled Immunoassay (Ligand
Immunoassay; e.g. EIA)
Primary
Classify serological tests
o Precipitation
o Agglutination
o Complement Fixation
o In Vitro Neutralization
Secondary
Classify serological tests
- Test for Phagocytosis
- Index of Phagocytosis
- Test for Opsonization
- Test for Chemotaxis
- Skin Test
- In Vivo Neutralization
Tertiary
