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MLPAO Clinical Chemistry Laboratory Practice 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 MLPAO Clinical Chemistry Laboratory Practice flashcards as text

  1. What does the coefficient of variation (CV%) represent in clinical chemistry quality assessment?

    Answer: The precision of a method expressed as a percentage of the mean

    The coefficient of variation (CV% = SD/mean × 100) expresses the precision (reproducibility) of an analytical method as a percentage of the mean. Lower CV% indicates better precision. It allows comparison of precision across different concentration levels and between different analytical methods.

  2. Which serum marker is used to monitor methotrexate therapy toxicity?

    Answer: Creatinine and liver enzymes

    Creatinine and liver enzymes (AST, ALT) are monitored during methotrexate therapy because the drug can cause both nephrotoxicity and hepatotoxicity. Methotrexate is primarily excreted by the kidneys, and impaired renal function can lead to drug accumulation and increased toxicity.

  3. What is the principle of immunoturbidimetry used in clinical chemistry analyzers?

    Answer: Measurement of light absorption by turbid antigen-antibody complexes in the direct light path

    Immunoturbidimetry measures the decrease in light transmitted through a solution as antigen-antibody complexes form and cause turbidity. The amount of light absorbed (decrease in transmitted light) is proportional to the concentration of the analyte. It differs from nephelometry, which measures scattered light at an angle.

  4. Why is it important to protect bilirubin specimens from light?

    Answer: Light photodegrades bilirubin, causing falsely decreased results

    Bilirubin is photosensitive and undergoes photoisomerization and photodegradation when exposed to light, particularly UV and fluorescent light. This causes falsely decreased bilirubin results. Specimens should be protected from light by wrapping tubes in foil or using amber-colored tubes.

  5. Which test is used to confirm the presence of a monoclonal protein identified on serum protein electrophoresis?

    Answer: Immunofixation electrophoresis (IFE)

    Immunofixation electrophoresis (IFE) is the confirmatory test for monoclonal proteins. After electrophoretic separation, specific antisera (anti-IgG, IgA, IgM, kappa, lambda) are applied to identify the heavy and light chain class of the monoclonal immunoglobulin, providing definitive characterization.

  6. What is the significance of measuring serum prealbumin (transthyretin)?

    Answer: Assessing short-term nutritional status and protein synthesis

    Prealbumin (transthyretin) has a short half-life of approximately 2 days, making it a sensitive indicator of recent changes in protein-calorie nutrition and hepatic synthetic function. It responds more rapidly to nutritional changes than albumin (half-life 20 days) and is useful for monitoring nutritional support.