Practice Test Geeks(MLS) Medical Laboratory Scientist Practice Test
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Diagnostic Procedures & Reporting Flashcards

7 cards from real MLS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Diagnostic Procedures & Reporting flashcards as text

  1. A urine dipstick is positive for blood, but microscopy shows no red blood cells. The most likely explanation is:

    Answer: Myoglobinuria or hemoglobinuria

    The dipstick peroxidase reaction detects heme, so both free hemoglobin (hemoglobinuria) and myoglobin (myoglobinuria) produce a positive result in the absence of intact RBCs.

  2. Which coagulation test result pattern is most consistent with disseminated intravascular coagulation (DIC)?

    Answer: Prolonged PT, prolonged aPTT, decreased fibrinogen, elevated D-dimer

    DIC consumes clotting factors and platelets while activating fibrinolysis, resulting in prolonged PT and aPTT, low fibrinogen, and markedly elevated D-dimer.

  3. A sputum Gram stain shows >25 squamous epithelial cells per low-power field. The laboratory should:

    Answer: Report the specimen as unsatisfactory and request a new sample

    More than 25 squamous epithelial cells per LPF indicates heavy oral contamination, rendering the specimen unsatisfactory for lower respiratory tract culture; a repeat specimen should be requested.

  4. The reference interval for a laboratory test is defined as the central:

    Answer: 95% of values from a healthy reference population

    Reference intervals are conventionally set to include the central 95% of values from a healthy reference population, meaning 2.5% fall below and 2.5% above the interval.

  5. A patient's serum appears grossly lipemic. Which of the following tests is MOST likely to be falsely elevated due to optical interference?

    Answer: Total protein by biuret method

    Lipemia causes turbidity that scatters light and can falsely elevate spectrophotometric assays such as total protein by the biuret method; direct ISE methods are less affected.

  6. Which finding on a peripheral blood smear is characteristically associated with iron deficiency anemia?

    Answer: Microcytes, hypochromia, and pencil cells (elliptocytes)

    Iron deficiency produces microcytic hypochromic red cells with pencil (cigar-shaped) cells due to reduced hemoglobin synthesis and altered membrane deformability.

  7. A laboratory result is reported with a delta check flag. This means:

    Answer: The result differs significantly from the patient's previous value

    A delta check compares the current result to the patient's most recent prior result; a flag indicates a change exceeding the defined limit, alerting staff to possible error or acute clinical change.