Exam Questions and CORRECT Answers
The laboratory receives a synovial fluid for acid fast culture. How should the tech proceed with
this culture?
a) Digest the sample for culture
b) Centrifuge the specimen and directly inoculate the culture
c) Perform a direct smear only
d) Reject the specimen - CORRECT ANSWER - Centrifuge the specimen and directly
inoculate the culture
Body fluids do not have normal flora like respiratory specimens so they don't need to be digested
prior. For body fluids: spin and use sediment to inoculate smears and culture media.
How does RhIg prevent anti-D production?
a) Mainly by suppressing the immune response after exposure to D+ cells
b) Mainly by clearing antibody sensitized D- RBCs from maternal circulation
c) Mainly by clearing IgG fetal antibodies from maternal circulation
d) Mainly by clearing maternal IgM antibodies from fetal circulation - CORRECT
ANSWER - Mainly by suppressing the immune response after exposure to D positive cells
RhIg suppresses immune response after exposure to D+ fetal cells and prevents the mother from
producing anti-D
Which test is not used as a screen for retroviruses in donated blood?
a) Antibody to HIV type 1 or type 2
b) Nucleic acid testing to detect HIV-1 RNA
,c) Antibody to HTLV types I and II
d) Nucleic acid testing for HCV - CORRECT ANSWER - Nucleic acid testing for HCV
NAT test is only used for HCV if there's a reactive HCV antibody test.
Also, HCV is not a retrovirus. Recall retroviruses only include HIV, HTLV-1, and HTLV-2
Which of the following would be the most characteristic finding in synovial fluid in a case of
pseudo gout?
a) Monosodium urate crystals
b) Calcium pyrophosphate crystals
c) Macrophage infiltration
d) Mixed RBC/WBC infiltration - CORRECT ANSWER - Calcium phosphate crystals
Calcium pyrophosphate crystals are characteristic of pseudo gout. Pseudo gout is a result of
endocrine disorders that produce high levels of calcium in serum
A cause of a false-positive result in the rapid plasma reagin (RPR) test for syphilis is:
a) Gastroenteritis
b) Gonococcal urethritis
c) Malaria
d) Streptococcal pharyngitis - CORRECT ANSWER - Malaria
RPR tests can show false positive results in the presence of infectious mononucleosis, SLE,
antiphospholipid antibody syndrome, hepatitis A, leprosy, and malaria.
The slide coagulase test is a rapid method for identifying which of the following organisms?
, a) Staphylococcus hominis
b) Streptococcus pneumoniae
c) Staphylococcus aureus
d) Neisseria gonorrhoeae - CORRECT ANSWER - Staphylococcus aureus
Coagulase slide test is used to differentiate S. aureus from coagulase-negative staphylococci
Elevation in conjugated bilirubin is most likely to be found in which of the following conditions?
a) Transfusion reactions
b) Erythroblastosis fetalis
c) Crigler-Najjar syndrome
d) Biliary obstruction - CORRECT ANSWER - Biliary obstruction
Bile duct obstruction will result in elevated conjugated (direct) bilirubin. The other three are
associated with increases in unconjugated (indirect) bilirubin
Which coagulation pathway is factor VII part of?
a) Intrinsic
b) Extrinsic
c) Common
d) Intrinsic and extrinsic - CORRECT ANSWER - Extrinsic
Extrinsic pathway: VII, III
Intrinsic pathway: XII, XI, IX, VIII
Common pathway: X, V, II, I