EXPERIMENT 16, 17, 18 Flashcards
Hepatitis C virus is an (?).
enveloped flavivirus
It is small, enveloped, (?) RNA virus.
single – stranded
Hepatitis C, previously called (?), was regarded as a diagnosis of exclusion because of the absence of specific serologic markers and unknown viral origin.
non – A, non – B (NANB) hepatitis
The general method of detecting infection with HCV is to observe the presence of antibodies to the virus in human (?).
serum or plasma
The etiologic agent of (?) is a human retrovirus known as human immunodeficiency virus (HIV – 1 and 2).
acquired immune deficiency syndrome (AIDS)
Retroviruses are defined as viruses that contain as single positive – stranded RNA, which contain the virus’ genetic formation, and a special enzyme known as (?) in their core.
reverse transcriptase
This enzyme enables the virus to convert viral RNA to DNA in contrast to the normal process of transcription where DNA is converted to RNA.
reverse transcriptase
The general method for detecting infection with HIV is to observe the presence of (?) to the virus.
antibodies
Dengue fever belongs to the group (?), and is transmitted by a day – biting mosquito vector, (?).
flavivirus
Aedes aegypti
Primary dengue infection, also known as (?), is associated with (?).
dengue fever
mild to high fever, headache, muscle pain and skin rash
This may progress to a secondary infection that often results in (?) and circulatory failure with noticeable fatality rate.
high fever with hemorrhagic episode
(?) to dengue virus enables serodiagnosis and differentiation between primary and secondary dengue infections.
Specific antibody response
16, 17, 18
REAGENTS:
Test kit (cassette) for anti – HCV
Test kit (cassette) for HIV – 1 and 2 antibodies
Test kit (cassette) for dengue IgG/IgM combo test
16, 17, 18
SAMPLE:
16, 17 Plasma or serum
18 Whole blood (anticoagulated with EDTA, heparin or oxalate), plasma or serum
(should be free form contamination, hemolysis and lipemia)
16, 17, 18
PRINCIPLE:
Immunochromatography
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
INVALID
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
17
Dispense (?) of the sample to the center of the sample well (marked as “S”) of the test card using the plastic dropper provided
3 drops (100 µL)
16
Dispense (?) of the sample to the center of the sample well (marked as “S”) of the test card using the plastic dropper provided
1 drop (10 µL)
16
Add (?) of sample diluent to the diluent well (marked as “D”) immediately after the specimen is added
2 drops
Diluent
16, HCV
Buffer
17, DENGUE
18
Dispense (?) of the sample to the center of the sample well (marked as “S1”) of the test card using a micropipette
5 µL
18
Add (?) of sample buffer to well-marked as “S”
2 drops
The assay starts with a sample applied to the sample well to which a sample diluent is immediately added.
The HCV antigen – colloidal gold conjugate embedded in the sample pad reacts with the HCV antibody present in serum or plasma sample forming conjugate – HCV antibody complex.
As the mixture is allowed to migrate along the test strip, the conjugate – HCV antibody complex is captured by an antibody – binding protein immobilized on a membrane forming a colored test band in the test region.
A negative sample does not produce a test line due to the absence of colloidal gold conjugate – HCV antibody complex.
The antigens used in the test are recombinant proteins corresponding to highly immunoreactive regions of HCV.
A colored control band in the control region appears at the end of the test procedure regardless of the result.
This control band is the result of colloidal gold conjugate binding to anti – HCV antibody immobilized on the membrane.
The control line indicates that the colloidal gold conjugate is functional.
The absence of the control band indicates that the test is invalid.
The assay starts with a sample applied to the sample well to which a sample diluent is immediately added.
A recombinant HIV antigen conjugated to colloidal gold embedded in the sample pad reacts with the HIV antibody present in serum or plasma, forming conjugate – HIV antibody complex.
As the mixture is allowed to migrate along the test strip, the conjugate – HIV antibody complex is captured by recombinant HIV antigen immobilized on a membrane forming a colored test band in the test region.
A negative sample does not produce a test line due to the absence of colloidal gold conjugate – HIV antibody complex.
The antigens used in the conjugate test are recombinant proteins that correspond to highly immunoreactive regions of HIV – 1 and HIV – 2.
A colored control band is the result of colloidal gold conjugate binding to anti – HIV antibody immobilized on the membrane.
The control line indicates that the colloidal gold conjugate is functional.
The absence of the control band indicates that the test is invalid.
(?) are immobilized on the nitrocellulose membrane respectively, as two individuals test lines (IgM line and IgG line) located in the test window of the test device.
Mouse antihuman IgM and IgG antibodies
The (?) in the test window is close to the sample well followed by IgM line.
IgG line
As the test sample flows through the membrane within the test device, the colored dengue – specific recombinant antigen – colloidal gold conjugate complexes with the specific antibodies (IgM and/or IgG) against the dengue virus, if present in the sample.
This complex moves further on the membrane to the test region where it is captured by the antihuman IgM and/or IgG antibodies coated on the membrane leading to the formation of a colored band which indicates a positive test result.
Absence of this colored band in the test window indicates a negative test result.
A built – in control line will always appear in the test window when the test has been performed properly, regardless of the presence or absence of anti – dengue virus antibodies in the specimen.
What is the best method used to detect infections due to rubella, Epstein-Barr and human immunodeficiency viruses?
antibody detection by EIA
Immunoassays are based on the principle of
a. separation of bound and free analyte
The presence of HBsAg, anti-HBc and often HBeg is characteristic of
a. early acute phase HBV hepatitis
An example of an organ specific disease with autoimmune antibodies is
Hashimoto’s thyroiditis
When testing a patient for HIV antibody, which of the following is used to confirm a positive screening test?
c. immunofluorescence
The Rapid Plasma Reagin test
a. is useful in screening for syphilis
What is the incubation period for mumps?
c. 14 to 18 days
Which of the following is a slide agglutination screening test for the detection of antibodies to several streptococcal antigens?
a. Anti-DNase B testing
b. ASO testing
c. Streptozyme testing
d. All of the above
C or D
Which of the following antigen detection procedures is the most specific test used to detect H. pylori?
Histological examination of gastric biopsy tissue
Which of the following is the causative agent of rocky mountain spotted fever?
R. rickettsia
The virus is transmitted by what mosquitoes of the daytime-biting Stegemyia family?
Aedes aegypti
Result suggesting a secondary or past infection with dengue virus
mild to high fever, headache, muscle pain and skin rash
Result suggesting either an acute primary or secondary dengue infection.
mild to high fever, headache, muscle pain and skin rash
Result indicates a late primary or early secondary acute infection.
mild to high fever, headache, muscle pain and skin rash
What is the amount of specimen dispensed on the sample well of the test
5uL
