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2010-11-06 19:11:10
Specimen Collection Control Quiz

Specimen Collection & Quality Control Quiz
Show Answers:

  1. What 4 things does an accurate chemical analysis depend on?
    • proper collection
    • perservation of sample
    • processing of sample
    • method of analysis
    • *all are equally important*
  2. What is the idea time for lab measurements to be performed?
    • Within 1 hr
  3. Why are specimens preserved?
    • 1. so the substance will not be altered
    • 2. specimens collected in a timely sequence should be stored until they can be analyzed at the same time
    • 3. samples retained or kept long enough to repeat if necessary
  4. What sample is most often used for chemical analysis?
    • Serum
    • *preferably fasting serum*
  5. What is the differance between serum and plasma?
    • 1. Serum is liquid portion with fibrinogen and clotting factors removed.
    • 2. Plasma is liquid portion of the circulating blood and it contains fibrinogen and clotting factors.
  6. What methods are used to preserve specimens?
    • 1. Part of specimen collection- sodium fluoride is the preservative in the gray top tube.
    • 2. We can refrigerate specimen, but must be brought to RT before testing.
    • 3. Separating the cells from the serum & plasma (the gold tube is usually used for separation)
    • 4. There are special requirements - ie. protect bilirubin from light.
    • 5. Freeze serum or plasma
  7. What is the silicone barrier used for?
    • To separate serum or plasma from cells.
    • Usually gold top tubes are used, the jell in the bottom of tube is (thixotropic gel).
    • 1. The jell prevents the shift of substances.
    • 2. It also prevents glycolysis.
  8. What vacutainer is used to collect serum and why?
    Gold top or red top tubes have no anticoagulant in the tubes.
  9. How is a gold top tube processed?
    • 1. inverted 5 times- do not remove stopper, or centerfuge imediately after drawing
    • 2. allow to clot upright- at least 30 mins. no more than 60 min.
    • 3. centerfuge at least 15 min. within 1 hr. of collection
    • 4. transfer to a labeled plastic screw cap vial
    • 5. Refrig (cool) or freeze
  10. What are the precautions when handling blood?
    • 1. gloves
    • 2. open stopper carefully away from you
    • 3. disinfect blood spills immediatly with 10% bleach or disinfectant
    • 4. discard tubes and sharps in crush & leak proof container
  11. Hemolyzed serum
    a clear red color to the serum or plasma
  12. Icteric or (hyperbilirubinemia, jundice)
    brownish yellow, patient may have jaundice or hepetisis
  13. Lipemic
    the serum or plasma is milky white
  14. Accuracy
    • the true or actual size
    • ex. bullseye
  15. Percision
    repeatability, reproducablility
  16. Normal value
    • average results of healthy individuals
  17. Batch or run
    • Specimen analyzed at the same time.
    • ex. a batach of cookies
  18. Standard
    • Calibrator used to set machine values
    • ex. alarm clock
  19. Control
    • Checks accuracy
    • Must fall within acceptable range before patient value reported
  20. Duplicate determination
    One of the specimens in the batch is measured twice and it check precision
  21. Proficiency survey
    • Specimens are sent to your lab
    • You analyze samples and send the results.
    • The agency will let you know how you did and how you compared to other labs
    • *meap testing for labs*
  22. What does a quality control program include?
    • 1. standards or calibrators
    • 2. controls
    • 3. duplicates
    • 4. profenecy service
  23. What 4 things does the control check for?
    • 1. machine or instrument
    • 2. reagents, strips, test cards, and starting manual
    • 3. operator
    • 4. environment temp. and humidity
  24. What steps should follow if a control fall outside of the acceptable range?
    • 1. document it ( in lab log)
    • 2. check everything
    • 3. retest the same control vial
    • 4. retest new vial
    • 5. recalirbrate the machine
    • 6. call customer service
  25. What is great about fasting?
    • reflects metabolic base line
    • avoids lipema (which is fat in blood)
  26. Controls
    • 1. Use universial precautions pooled serum/plasma, control may have human antigens.
    • 2. Unopened exp. date, midnight, last day of month opened.
    • ex. 2011-07 is July 31, 2007 at midnight
    • 3. Results reported according to lot #
    • 4. Keep QC results 2 years
    • 5. CLIA wavied quality contrl testing according to manufacturers instruction. (clia has 3 levels of testing. waived, moderate and high)