Specimen Handling and Processing

Study Notes

Pre-Analytical Phase

The pre-analytical phase consists of all steps taken before actual testing of the sample, and it is estimated that 46% to 68% of all laboratory errors occur during this phase.

Specimen Handling

Routine handling of specimens involves mixing tubes by inversion (3-10 gentle inversions) and transporting them with the stopper up in plastic bags with a biohazard logo, liquid-tight closure, and a slip pocket for paperwork.
Routine blood specimens should arrive at the lab within 45 minutes, and centrifugation should occur within 1 hour of arrival.

Special Handling Requirements

Body temperature specimens should be collected in a pre-warmed tube and transported at or near normal body temperature (37°C) using portable heat blocks.
Chilled specimens should be immersed in a slurry of crushed ice and water and tested immediately or refrigerated.
Light-sensitive specimens should be wrapped in aluminum foil or placed in a light-blocking amber-colored container.

Specimen Processing

In the central processing area, specimens are identified, logged/accessioned, sorted by department and type of processing required, and evaluated for suitability for testing.

Specimen Suitability

Specimens are rejected due to hemolysis, insufficient amount, clotting, inadequate/inaccurate/missing ID, wrong/outdated tube, improper handling, wrong collection time, exposure to light, delay in testing, or delay/error in processing.

Centrifugation

Centrifugation separates cells and plasma or serum using a centrifuge machine.
Tubes awaiting centrifugation should have stoppers remaining on to prevent inaccurate results, evaporation, and contamination.
Tubes must be balanced during centrifugation, and plasma specimens can be centrifuged without delay, while serum specimens must be completely clotted before centrifugation.

Stopper Removal

Stopper removal may be done using devices or robotics, or manually with a face shield or splash shield, and gauze or tissue covering the stopper.
Stoppers should be pulled straight up and off.

Aliquot Preparation

An aliquot is a portion of the specimen used for testing, prepared by transferring a portion of the specimen into one or more tubes labeled with the same ID information as the specimen tube.
Aliquots are used for multiple tests ordered, tests performed on different instruments or in different areas.

Non-Blood Specimen Labeling and Handling

Non-blood specimens should be labeled with the same ID information as blood specimens, including type and/or source of specimen.
Labeling should be applied to the container, not the lid.
Familiarity with handling requirements is necessary to protect the integrity of the specimen and ensure accurate test results.
All body substances are potentially infectious.

Urine Specimens

Urine is the most frequently analyzed non-blood body fluid, readily available, easy to collect, and inexpensive to test.
Urine analysis can aid in providing information on many of the body's major metabolic functions, monitoring wellness, diagnosing and treating urinary tract infections, and detecting and monitoring diseases.

Description

Learn about the critical pre-analytical phase of laboratory testing, where 46-68% of lab errors occur. Understand the importance of proper specimen handling, including mixing tubes and transporting specimens safely. Improve your knowledge of laboratory procedures and reduce errors.