Laboratory Techniques and Procedures Questions and Answers Flashcards
6 cards from real MLPAO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Laboratory Techniques and Procedures Questions and Answers flashcards as text
What technique is used to separate DNA fragments by size during gel electrophoresis?
Answer: Migration through an agarose gel matrix under an electrical current
DNA fragments migrate through an agarose gel under electrical current — smaller fragments move faster through the gel matrix than larger fragments, separating them by size.
What is the principle of the polymerase chain reaction (PCR) in molecular diagnostics?
Answer: Amplification of specific DNA sequences through repeated cycles of denaturation, annealing, and extension
PCR amplifies specific DNA sequences exponentially through repeated thermal cycles: denaturation (94-98°C) separates strands, annealing (50-65°C) allows primers to bind, and extension (72°C) allows Taq polymerase to copy the target.
In clinical microbiology, what is the purpose of inoculating a blood agar plate and a chocolate agar plate simultaneously when processing a respiratory specimen?
Answer: Blood agar detects beta-hemolytic organisms; chocolate agar supports fastidious organisms like Haemophilus and Neisseria that require growth factors released by heated RBCs
Blood agar supports most bacteria and shows hemolysis patterns; chocolate agar (heated blood agar) releases NAD and hemin from lysed RBCs, supporting fastidious organisms such as Haemophilus influenzae and Neisseria species.
Which laboratory method is used as the reference (gold standard) for diagnosing malaria?
Answer: Microscopic examination of Giemsa-stained thick and thin blood films
Microscopic examination of Giemsa-stained thick and thin blood films is the reference standard for malaria diagnosis, allowing species identification and parasitemia quantification.
What type of pipette is most appropriate for delivering a precise volume of 100 μL for an ELISA assay?
Answer: Calibrated micropipette (100 μL fixed or adjustable)
A calibrated micropipette set to 100 μL delivers precise, accurate volumes for immunoassays like ELISA. Accuracy is critical because volume errors directly affect the antigen-antibody ratio and results.
What is the CMLTO-recognized clinical significance of performing an extended red blood cell antigen typing before first transfusion in a patient with sickle cell disease?
Answer: To establish a baseline antigen profile to guide compatible RBC unit selection and prevent alloimmunization
Extended RBC antigen typing (Rh, Kell, Duffy, Kidd, MNS systems) before first transfusion establishes the patient's antigen profile, allowing selection of phenotypically matched units to minimize alloimmunization risk.