EXPERIMENT 13, 14, 15 Flashcards
is useful in the diagnosis of Streptococcal infection and its
relative effects on organs, especially the heart and kidneys.
Anti – Streptolysin O (ASO) test
is a corkscrew – shaped, gram – negative rod that infects the mucous layer of the stomach.
Helicobacter pylori
Helicobacter pylori is the most common of (?), and is etiologically involved in gastric ulcer, duodenal ulcer, gastric adenocarcinoma and primary gastric B – cell lymphoma.
gastritis
Hepatitis B virus is a member of the (?). It is a (?) virion, with an (?) nucleocapsid core containing a rapidly (?) DNA genome.
Hepadnaviridae family
42 mm enveloped
icosahedral
double stranded circular
The envelope contains a protein called the (?), which is important for laboratory diagnosis and immunization.
surface antigen (HBsAg)
is the earliest serological marker that indicates the presence of acute infection.
HBsAg
HBsAg is also indicative of
chronic infection.
13
REAGENTS:
ASO latex reagent
Positive control
Negative control
Normal Saline Solution (0.85 – 0.90% NaCl)
13
SAMPLE:
Serum (should be free from contamination, hemolysis and lipemia)
13
PRINCIPLE:
Latex Agglutination
14
REAGENTS:
Test kit (cassette) for Helicobacter pylori antibody test
14
SAMPLE:
Plasma or serum (should be free from contamination, hemolysis or lipemia)
14
PRINCIPLE:
Immunochromatography
15
REAGENT:
Test kit (cassette) for HBsAg
15
SAMPLE:
Plasma or serum (should be free from contamination, hemolysis and lipemia)
PRINCIPLE:
Immunochromatography (Solid Phase “Sandwich” Immunoassay)
The (?) is a rapid slide agglutination test for the direct detection and semi – quantitation of anti – streptolysin O.
anti – streptolysin O (ASO) latex test
the antigen, a particulate latex suspension coated with streptolysin O, agglutinates in the presence of specific antibodies present in the sera of patients with
Streptococcal β – hemolytic infection.
Helicobacter pylori antibody test (?) in a cassette format.
chromatographic lateral flow test device
Colloidal gold conjugated Helicobacter pylori antigens are dry – immobilized at the end of nitrocellulose membrane strip.
Helicobacter pylori antigens are bound at the test zone (T).
when the sample is added, it migrates by capillary diffusion rehydrating the gold conjugate.
If anti – Helicobacter pylori antibodies are present in the sample, the antibodies will bind to the gold conjugated antigens forming particles.
These particles will continue to migrate along the strip until the test zone (T) where they are captured by Helicobacter pylori antigens generating a visible red line.
If there are no anti – Helicobacter pylori antibodies in the sample, no red line is formed in the test zone (T).
A built – in control line will always appear in the control zone (C) when the test has been performed properly, regardless of the presence or absence of anti – Helicobacter pylori antibodies in the specimen.
HBsAg test is a colloidal gold enhancement immunoassay that detects hepatitis B surface antigen in human serum or plasma.
The sample initially reacts with the monoclonal antibody – colloidal gold conjugate on the sample pad.
This mixture migrates across the membrane by capillary action and reacts with the anti – HbsAg in the test region.
If the sample contains HBsAg, a line will form on the membrane at this point.
If the antigen is not present in the sample, no line is formed, indicating a negative result.
The mixture continues to flow to the current area of the membrane, where it forms a line indicating the test result is valid.
13
Using a semi – automatic pipette, add (?) of normal saline solution to circles 2, 3, 4 and 5
50 µL
Add (?)of patient sample to circle 1 and 2
50 µL
Transfer (?) of mixture from circle 2 to the saline in circle 3.
50 µL
Perform serial dilution in the same manner until the last circle, discarding (?) at the end
50 µL
Using the disposable pipette or stirrer, spread the diluted sample over the entire area of each circle starting at (?) and moving backwards to the next, reaching until (?)
circle 5
circle 1
Add (?) latex reagent to each circle containing the sample
one (1) drop
Rotate the test cards or agglutination slides at
100 rpm for 2 minutes
Guide in the Interpretation of Results:
Examine macroscopically for the presence of or absence of clumps or agglutination within (?) after removing the test card or agglutination slide from the rotator
1 minute
The presence of visible agglutination indicates the
presence of anti – streptolysin O ≥ 200 IU/mL
✓ Negative result
✓ Positive result:
✓ Negative result No agglutination
✓ Positive result: Presence of agglutination
Computation:
ASO (IU/mL) =
Limit of sensitivity =
limit of sensitivity x highest dilution with positive reaction
200 IU/mL
ASO titers < 200 IU/mL are found in (?) of the healthy adult population, with values higher (up to 300 IU/mL) among children
95%
14
Dispense [?] of the sample to the center of the sample well (marked as “S”)
3 drops (120 – 150 µL)
Distinct colored band appears on the Test region (T) in addition to a colored band on the Control region (C)
POSITIVE
No colored band appears on the Test region (T) but distinct colored band appears on the Control region (C)
NEGATIVE
Neither Test (T) nor Control (C) colored band appears, or colored band only appears on the test region (T) but not on the Control region (C)
INVALID
The specimen should be tested again using a new device
INVALID
15
Dispense [?] of the sample to the center of the sample well (marked as “S”)
3 drops (100 µL)
