PMLS P2

• The result of a test is compromised when the proper collection procedures, storage, processing, and transporting protocol were not followed in the preanalytical phase
• Studies show that approximately 48% to 68% of laboratory result failures are due to prior analysis phase mishandling or error
• Routine Handling


  1. Phlebotomist should adhere to time limits set for delivery of specimens to the laboratory

  2. Mixing tubes by inversion- usually between 3 to 10 inversions

  3. Transporting specimens- should be transported with the stopper to avoid contact between contents and the stopper, minimize agitation of the specimen, and aid clot formation for serum tubes
• Special Handling - Body temperature

  1. Specimen that precipitate or agglutinate if allowed to cool below body temperature should be transported at near body temperature which is 37 ̊C

  2. The tubes should also be pre-warmed at 37 ̊C and portable heat blocks are used during transport which could hold the temperature for 15 minutes from removal from the incubator

  3. A heel warmer can be used for specimen that can withstand a temperature slightly higher than 37 ̊C
• Chilled specimens


  Chilling slows the metabolic process which could affect the results for some specimens
• Handling chilled specimens


  Completely submerged in crushed ice and water slurry during transport and immediately tested or refrigerated if needed
• Chilled specimens


  • Adrenocorticotropic hormone (ACTH), acetone, Angiotensin-converting enzyme (ACE), ammonia, catecholamines, free fatty acids, gastrin, glucagon, homocysteine, lactic acid, parathyroid hormone (PTH), ph/blood gas (if indicated), pyruvate, renin
• Handling light-sensitive specimens


  1. The phlebotomist should wrap the tube with aluminum foil or use light-blocking amber-colored containers

  2. In the absence of an amber container, we should use the carbon copier to cover the specimens that are light-sensitive
• Light-sensitive specimens


  • Bilirubin, Carotene, Red cell folate, serum folate, Vitamin B2, Vitamin B6, Vitamin B12, Vitamin C, urine porphyrins, and urine porphobilinogen
• Criteria for specimen rejection


  1. Specimen is not identified properly

  2. It has inadequate volume to complete the test

  3. Hemolysis

  4. The use of wrong tube for collection

  5. Outdated tube

  6. Improper handling (improper mixing)

  7. Contaminated specimen

  8. Insufficient specimen or "Quality Not Sufficient" (QNS)

  9. Incorrect collection time

  10. Exposure to light

  11. Did not follow testing time limits

  12. Delay or error in processing
• Time constraints and exceptions for delivery and processing of specimens

  1. Routine blood specimens are expected to reach the laboratory within 45 minutes

  2. For specimens that need centrifugation, it should be done in 1 hour

  3. Specimen marked as "STAT" or "emergency" takes priority over all other specimen in terms of transportation, processing and testing

  4. Exceptions to the time limit rule: Blood smear from EDTA specimen, EDTA specimen for CBC, EDTA specimen for erythrocyte sedimentation rate (ESR) determination, EDTA specimen for reticulocyte counts, Glucose test drawn in sodium fluoride tubes, Prothrombin time (PT)
• OSHA stands for Occupational Therapy and Health Administration
• OSHA-required equipment protective worn processing specimen

  Wearing gloves to prevent contact with blood, laboratory gown, laboratory coats, and masks
• Centrifugation


  1. The amount of specimen should be balanced with the water or any balancer

  2. The water in the centrifuge is called a balancer

  3. Leave the stoppers on the tube before and during centrifugation to avoid contamination, evaporation, aerosol formation, and pH changes

  4. Tubes of the same size and volume of specimen should be placed opposite one another

  5. Plasma specimen collected in tubes with anticoagulants should be centrifuged immediately and without any delay

  6. Serum specimen needs to be completely clotted prior to centrifugation, which normally takes around 30 to 60 minutes at room temperature

  7. Most of the test needs the stopper to be removed to obtain the serum or plasma

  8. A gauze or tissue is used to cover the stopper to catch drops of blood that may leak or to catch aerosol that maybe released during the process

  9. The tube stoppers should be removed by pulling it straight up and off the tube
• Aliquot preparation


  1. An aliquot of specimen refers to a portion of a sample specimen taken for chemical analysis or testing

  2. This is prepared when multiple tests are ordered on a single specimen

  3. The preparation is done by transferring a portion of the specimen into one or more tubes that are labeled with the same information as the original specimen tube using a disposable transfer pipettes

  4. Do not put specimen with different anticoagulants in the same aliquot tube

  5. Make sure to cover the tube as soon as it is filled