Specimen Transportation
  Specimen Delivery
  Specimen Packaging
  Syringes and Needles
  Serum Preparation
Specimen Storage
  Interferring Substances
Handling Procedures Specimen Storage

  1. Serum and plasma should always be kept covered to minimize evaporation and contamination.

  2. Serum or plasma should be tested within 4 hours.

  3. If the delay before testing is going to be longer than 5 hours, the specimen should be refrigerated at 2-8 degrees C.

Handling Considerations

Blood samples should be processed as soon as possible after being drawn. The following general precautions should be observed:

  1. Keep the specimen tubes capped. This should be done for safety reasons as well as for specimen preservation.
  2. Avoid specimen agitation. Hemolysis (the breakdown of red blood cells) will occur when the specimen is agitated. A certain amount of hemolysis is unavoidable, but it should be minimal. Badly hemolyzed specimens are unacceptable for Blood Bank, Coagulation, and most Chemistry procedures. Avoid shaking the specimen and always use gentle inversion to mix specimens. Always handle specimens with care.

    NOTE: Refer to Hemolyzed Samples section of Procedure Manuals for specific information.

  3. Avoid specimen exposure to light. Certain specimens, such as carotenes and most vitamins, break down when exposed to light. If these levels are being drawn, use aluminum foil to wrap specimen to prevent light exposure.

    NOTE: Refer to Lab Handbook for test specific information.

  4. Adhere to specimen time constraints. Timing is critical in most Chemistry and Hematology procedures. Follow manufacturer's recommendations for minimum and maximum times which specimens may be left in the tube. Be aware that most Hematology procedures require that the specimen remain in the tube for a minimum period of time to stabilize the anticoagulants. In general, Hematology procedures involving an automated WBC differential are among the most time sensitive. Serum specimens should be separated from whole blood within 2 hours of specimen collection.

    It is imperative that Hematology specimen containers are properly filled to ensure the proper blood to anticoagulant ratio. Under-filled containers are unacceptable. It is not recommended to transfer Hematology specimens to another tube; deliver to the laboratory as soon as possible. If there is a delay, contact the Hematology laboratory for further instructions.

  5. Refrigerate specimens not tested immediately.

    Anticoagulated venous specimens should be stored at 2-8 degrees C if they will not be tested within 4 hours. Heat may cause hemolysis. Serum specimens should be separated from whole blood before being refrigerated.

Sources of Error

  1. Diet influences certain tests which require fasting prior to specimen collection. Prolonged fasting will influence certain test results as well. Blood drawn immediately after a meal will probably have different levels of potassium, phosphorus, glucose, triglycerides, and alkaline phosphatase than specimens taken 4 hours after eating.

    NOTE: Refer to Lab Handbook for test specific information.

  2. Tourniquets left on for more than 1 minute or vigorous hand exercise will elevate potassium and lactic acid levels and decrease blood pH.
  3. Anticoagulated specimens containing clots should be discarded.
  4. Hemolysis causes increased levels of acid phosphatase, bilirubin, CPK, LDH, magnesium, potassium, AST and ALT and shortened coagulation studies (PT, PTT).
  5. Serum in prolonged contact with the clot will result in changes in glucose, iron, LDH, and potassium levels.
  6. No specimens are accepted with attached needles. The potential for transmission of blood-borne diseases is greatest when needles and sharp instruments are used in direct patient care or in a clinical laboratory setting away from the patient environment. Extreme precautions should always be used in handling sharp objects of any kind.

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