Standard Operating Procedure: Laboratory Testing Protocols

This document establishes the standardized workflow for the execution of laboratory tests to ensure data integrity, personnel safety, and compliance with institutional and regulatory standards. Adherence to these procedures is mandatory for all laboratory staff to minimize analytical error, ensure reproducibility, and maintain a safe environment. All procedures must be conducted in accordance with Good Laboratory Practice (GLP) and specific departmental safety guidelines.

Phase 1: Pre-Analytical Preparation

• Verification of Orders: Cross-reference testing requests with the Laboratory Information Management System (LIMS) to ensure specimen type, volume, and urgency align with the intended test.
• Equipment Calibration: Verify that all analytical instruments (e.g., pipettes, centrifuges, analyzers) have valid calibration stickers and have passed daily start-up self-checks.
• PPE Donning: Ensure appropriate Personal Protective Equipment (PPE) is worn, including lab coat, nitrile gloves, and eye protection, prior to handling any biological or chemical samples.
• Environment Check: Verify that ambient temperature and humidity in the laboratory meet the requirements specified in the instrument’s operation manual.

Phase 2: Specimen Handling and Processing

• Specimen Identification: Verify two patient identifiers (e.g., full name and DOB/MRN) on both the specimen label and the LIMS entry.
• Integrity Assessment: Inspect the sample for signs of hemolysis, lipemia, icterus, or insufficient volume before processing.
• Sample Preparation: Perform required aliquoting, centrifugation, or dilution exactly as specified by the Test Method Manual.
• Reagent Verification: Confirm all reagents are within their expiration dates and stored at the correct temperatures; document lot numbers if required by the protocol.

Phase 3: Analytical Execution

• Loading Samples: Place samples into the analyzer according to the prescribed mapping or load list. Ensure barcodes are readable and oriented correctly.
• Control Analysis: Run Quality Control (QC) samples (High/Low) prior to processing patient samples to validate the assay’s performance.
• Data Monitoring: Monitor the instrument during the run for error flags, hardware warnings, or unexpected interruptions.
• Validation of Results: Compare internal QC data against established Westgard Rules or moving averages before releasing patient results.

Phase 4: Post-Analytical and Reporting

• Review and Release: Conduct a final clinical review of results. Flag any "Critical Values" and ensure immediate notification to the ordering physician per institutional policy.
• Specimen Storage: Properly label and archive remaining patient specimens in the designated storage area (e.g., 4°C or -20°C) for the mandatory retention period.
• Decontamination: Perform a post-run wipe-down of all work surfaces with approved disinfectant.
• Waste Disposal: Dispose of hazardous waste, sharps, and biological materials according to biohazard protocols.

Pro Tips & Pitfalls

• The "Double-Check" Habit: Never rely on visual confirmation alone. Always scan barcodes to confirm identity. Human visual errors are the leading cause of pre-analytical testing failures.
• Avoid "QC Bias": Do not rerun controls multiple times hoping to achieve a "pass" result without investigating the root cause of the initial failure.
• Documentation is Key: If a deviation occurs, document it immediately. An undocumented action in a laboratory environment is considered a failure of protocol, regardless of the test outcome.
• Pipetting Accuracy: Always use the correct volume range for the pipette being used to prevent volumetric error.

FAQ

Q: What should I do if a QC result falls outside the acceptable range? A: Cease all patient testing on that assay immediately. Identify the potential cause (expired reagents, expired controls, or calibration issues), resolve the issue, repeat the QC run successfully, and document the corrective action in the QC log.

Q: How long must patient samples be stored after testing? A: Retention periods vary by test type and local regulatory requirements. Refer to the 'Specimen Retention Schedule' in the Lab Policy Manual for specific timeframes.

Q: What is the procedure if a patient sample is received with inadequate labeling? A: The sample must be rejected. Do not attempt to guess the patient identity. Mark the sample as "Rejected - Improper Labeling" in the LIMS and contact the nursing station or requesting provider to facilitate a recollect.