Introduction & Basic Serologic Techniques Flashcards
________as diagnostic tests in clinical laboratory is for diagnosis of infectious diseases & non-infectious diseases.
Serologic testing
microbiology, chemistry, toxicology, immunology, hematology, surgical pathology, cytopathology, immunohematology (blood banking) —
Immunologic testing —
_______ may now also be done at home, using kits.
Rapid testing
_______ technology also developed of highly specific and sensitive immunoassays.
Monoclonal antibody (MAb)
Immunologic / Serologic Techniques uses:
- Test antigens in body fluids or on cells.
- Determine immunoglobulins and antibodies in body fluids, on cells or in tissues.
- Detect immune complexes in body fluids and tissues.
- Quantitate and characterize complement system components.
- Test functions of phagocytes, lymphocytes, eosinophils etc.
- Tissue typing and mixed lymphocyte reaction
_____ is concerned with antigen-antibody reactions in-vitro.
SEROLOGY
➢ A written procedural protocol & document of techniques and policies that includes:
a. Specimen /collection and Storage
b. Reagents, Supplies and Equipment
c. Procedural Methods
d. reference Values
Procedures Manual
Blood Specimen Preparation:
➢ Promptly separate _____ from the clot after centrifugation.
➢ If serum is contaminated with rbc, it should be ________.
➢ Avoid excessive ___ and ________
➢ Refrigerate serum if test ______ be performed immediately.
➢ Freeze serum at _____ if testing cannot be done within _____
➢ Some procedures require use of_____. It destroys complement activity as it is known to interfere with the reactions of certain tests
serum re-centrifuged heat and bacterial contamination cannot -20ºC; 72 hours. inactivated serum
Ways of inactivating Complement:
a. Heating at ____ for 30 minutes or _____ for 3 minutes. Specimens can be _____, though, by heating at _____ for 10 minutes when more than ____ has elapsed.
b. Aging
c. Non-serological means:
● _______
● ______, e.g. (acids, alkalis, alcohol), enzymes, yeast or bacterial cells, tissue extracts
● _______
➢ If inactivation of Complement is not done, it can interfere with the reaction of some tests. Example:
a. In _______, it can agglutinate latex particles and cause false positive reaction.
b. Can also cause lysis of indicator cells in _______
56ºC; 61ºC; reinactivated; 56ºC; 4 hrs
c. vigorous agitation
Chemical treatment
Hemolysis
Agglutination tests
Hemagglutination assay
Specimens for Serological Testing
Serum Urine (pregnancy test & for UTI) Other specimens - CSF - Other body fluids - Swabs of various exudates and discharges
- Serum specimen
● Avoid: _______
➢ Hemolysis
➢ Lipemia
➢ Bacterial contamination
Collect specimens after thorough cleansing of the external genitalia.
● Observe timing of collection.
Urine (Pregnancy Test & for UTI)
Collect specimens into a suitable container to prevent ___ changes.
in-vitro
Proper handling and storage of the specimen until testing is essential.
Follow established protocol in specimen collection requirements & conditions for each assay.
!
Collect Blood _____ a meal to avoid the presence of ____.
before
chyle
____ serum may yield valid results, but may interfere with some.
Icteric or turbid
Avoid contamination with _____, such substances may have a denaturing effect on serum proteins and make the specimen unsuitable for testing.
alkali or acid
To obtain specimens for serologic testing, consider the phase of the disease and the condition of the patient at the time of specimen collection.
For Antibody Testing
If serum is tested for antibody levels with specific infectious organism, draw the blood during:
A. Acute phase of the illness.
B. Convalescent phase.
● Note a difference in the amount of antibody present or antibody titer.
● Some diseases, however, may not manifest a rise in titer until months after the acute infection.
This is acute & convalescent serum
Pipettes –
Graduated Pipettes or Measuring Pipettes
Serologic Pipettes
Great accuracy is not required.
Graduated Pipettes or Measuring Pipettes
Primarily used for measuring reagents, but are not sufficiently calibrated to standards or control solutions, unknown specimens or filtrates. Marked with a TC.
Graduated Pipettes or Measuring Pipettes
Has a frosted ring or etched band at the non-calibrated end and calibrations extend to the tip; is marked with a TD.
Serologic Pipettes
Empty by gravity and expel remaining solution to deliver the full volume
Serologic Pipettes
Pipettes & Pipetting Techniques:
- Manual pipets;
- Automatic Pipets; and
- Micro-pipettors.
Accidents in laboratory frequently result from improper pipetting technique. ______ instead of mechanical suction is the greatest potential hazard. Hence, ________ is never acceptable in the clinical laboratory
Mouth pipetting
____ is an indicator of relative concentration
Dilution
The _____or concentration is the central concept of serologic testing.
Rise in titer
the reciprocal of the highest dilution of the patient’s serum in which antibody is still detectable.
○ the highest dilution of the serum that gives a positive reaction with the antigen.
Antibody titer
A _____indicates a relatively high concentration of the antibody in the serum.
The greatest dilution of the sample that yields a _____ is the endpoint.
high titer
positive result
For most ______, increase in the patient’s titer of 2 doubling dilutions over several weeks indicates a current infection. e.g. __ to a positive result of __.
pathogenic infections
1:8; 1:32
For most ______, increase in the patient’s titer of 2 doubling dilutions over several weeks indicates a current infection. e.g. __ to a positive result of __.
pathogenic infections
1:8; 1:32
● It is any dilution where the concentration decreases by the same quantity in each successive step.
Serial Dilution
____ are always made by taking a set quantity of the initial dilution and adding it successively to tubes with the same volume.
Serial dilutions
_____are multiplicative, so each successive dilution would be multiplied by the dilution factor.
Serial dilutions
