MDC1010 Sample Prep 2024

Importance of Sample Preparation

  • Essential for accurate laboratory results.

  • Involves three pre-analytical phases:

    • Sample Collection

    • Sample Transportation

    • Sample Preparation Technique

  • Errors in these phases can lead to faulty results.

Steps in Sample Preparation

Sample Reception and Checking

  • Samples must meet quality criteria before acceptance.

  • Acceptance Criteria:

    1. Correct packaging

    2. Leak-free package

    3. Proper transportation conditions

    4. Adequate specimen quality

    5. Sufficient sample volume

    6. Completeness of the Request Form

    7. Concordance of Request Form with sample details

Separation Techniques

  • Physical Separation:

    • Sedimentation (gravity, centrifugal)

    • Filtration (separating particulate from soluble matter)

    • Dialysis (for macromolecules)

  • Chemical Separation:

    • Precipitation (forming insoluble substances)

    • Crystallization (purifying through saturation)

Aliquot and Storage of Samples

  • Aliquots: Represent a portion of a sample for testing or storage.

  • Considerations for aliquots include:

    • Required amount and conditions

    • Containers for storage

    • Proper labeling

Laboratory Test Processing Phases

  • Pre-Analytical Phase: Involves clinical questions and sample preparation.

  • Analytical Phase: Includes performing tests and analysis.

  • Post-Analytical Phase: Results are reported and verified.

Sample Handling Procedures

  • SOP for Sample Reception & Processing:

    1. Checking sample integrity.

    2. Rejection of unsuitable samples with proper documentation.

    3. Laboratory register for accepted samples.

    4. Proper labeling and traceability.

    5. Periodic review of sample volume requirements.

Sample Storage Strategies

  • Maintain sample integrity with temperature monitoring and containment.

  • Develop policies for sample retention and proper disposal according to regulations.