MLPAO Specimen Processing and Handling Questions and Answers 2

Question 1

What is the maximum acceptable cold ischemia time for a kidney transplant organ from declaration of brain death to organ reperfusion?

Accepted Answer

12-36 hours

Answer

Cold ischemia time for kidneys is generally acceptable up to 24-36 hours with proper cold perfusion preservation, though outcomes improve significantly with shorter times (<12 hours).

Question 2

A CSF specimen is collected in three tubes. Which tube should be sent to the microbiology laboratory for culture?

Accepted Answer

Tube 2 — least likely to be contaminated with skin flora

Answer

Tube 2 is sent for microbiology culture because it is least likely to be contaminated with skin flora from the puncture site, which is most likely to contaminate Tube 1.

Question 3

A laboratory receives a serum specimen for cortisol measurement labeled 'AM cortisol — 0900 hours.' The specimen was collected at 0900 but not processed until 1600. Is this specimen acceptable?

Accepted Answer

No, cortisol may degrade; check stability guidelines and consider recollection if outside stability limits

Answer

Cortisol stability should be verified against laboratory stability data. Most guidelines indicate serum cortisol is stable for 4-8 hours at room temperature and longer if refrigerated, but the 7-hour delay warrants stability verification.

Question 4

What does 'aliquoting' a specimen mean in laboratory specimen processing?

Accepted Answer

Dividing a primary specimen into smaller portions for multiple tests or storage

Answer

Aliquoting involves transferring measured portions of a primary specimen into secondary tubes or containers to allow multiple tests to be performed from a single collection or for archival storage.

Question 5

Which of the following correctly describes the impact of lipemia on clinical chemistry test results?

Accepted Answer

Lipemia causes interference in multiple assays by light scattering, false volume exclusion, and reagent interference

Answer

Lipemia causes multiple interferences: turbidity affects photometric assays (light scatter), lipid particles displace aqueous volume (pseudohyponatremia with indirect ISE), and lipids can interfere with reagent chemistry.

MLPAO - Medical Laboratory Professionals Association of Ontario Practice Test

MLPAO - Medical Laboratory Professionals Association of Ontario Practice Test

MLPAO Specimen Processing and Handling Questions and Answers 2