Standard Operating Procedure for Preventing Cross-Contamination of Samples in BA/BE Studies
| Department | BA-BE Studies |
|---|---|
| SOP No. | SOP/BA-BE/114/2025 |
| Supersedes | SOP/BA-BE/114/2022 |
| Page No. | Page 1 of 9 |
| Issue Date | 17/04/2025 |
| Effective Date | 20/04/2025 |
| Review Date | 17/04/2026 |
1. Purpose
To establish a robust and standardized procedure for the prevention of cross-contamination of clinical samples during collection, processing, labeling, storage, and transport in Bioavailability/Bioequivalence (BA/BE) studies.
2. Scope
This SOP applies to all personnel involved in clinical sample handling, including collection, separation, labeling, aliquoting, storage, and transfer processes conducted at clinical and bioanalytical facilities.
3. Responsibilities
- Phlebotomist: Collects samples using sterile equipment and ensures no reuse of consumables.
- Processing Technician: Handles only one subject’s samples at a time and disinfects work area between batches.
- Quality Assurance (QA): Conducts periodic audits and reviews sample tracking logs for compliance.
- Bioanalytical Staff: Verifies sample integrity upon receipt and inspects packaging for leaks or cross-labeling.
4. Accountability
The Head of Clinical Laboratory Operations is accountable for ensuring that all measures to prevent cross-contamination are in place, implemented, and periodically reviewed.
5. Procedure
5.1 General Laboratory Practices
- All sample handling personnel must:
- Wear gloves, masks, and lab coats at all times
- Change gloves between subjects
- Disinfect benchtops and centrifuges with 70% IPA before and after use
5.2 Sample Collection
- Use pre-labeled, single-use vacutainers or blood collection tubes for each subject.
- Maintain individual sample trays to avoid mixing of subject IDs.
- Complete Annexure-1: Sample Collection Checklist for each subject at each timepoint.
5.3 Sample Processing
- Process samples from one subject at a time.
- Aliquot using separate, disposable pipette tips for each sample.
- Ensure one operator handles both labeling and aliquoting to prevent misidentification.
- Record processing times and personnel on Annexure-2: Sample Processing Log.
5.4 Storage and Segregation
- Store samples in properly labeled cryoboxes, with:
- Unique volunteer ID
- Timepoint
- Date
- Do not mix samples from different studies in the same storage rack or freezer compartment.
5.5 Sample Transfer
- Use sealed containers with absorbent materials for inter-department or site transfer.
- Document chain of custody using Annexure-3: Sample Transfer Log.
- Inspect each sample’s label upon receipt and verify against manifest.
5.6 Deviation Handling
- Any suspicion or confirmed instance of contamination must be reported to QA immediately.
- Initiate deviation report using Annexure-4: Contamination Incident Report.
- Perform root cause analysis and implement CAPA.
6. Abbreviations
- BA: Bioavailability
- BE: Bioequivalence
- QA: Quality Assurance
- IPA: Isopropyl Alcohol
- CAPA: Corrective and Preventive Action
7. Documents
- Sample Collection Checklist – Annexure-1
- Sample Processing Log – Annexure-2
- Sample Transfer Log – Annexure-3
- Contamination Incident Report – Annexure-4
8. References
- ICH E6(R2) – Good Clinical Practice
- WHO Guidelines on Biological Sample Handling
- Schedule Y – Drugs and Cosmetics Rules
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Sample Collection Checklist
| Volunteer ID | Timepoint | Tube Label Verified | Gloves Changed | Phlebotomist Signature |
|---|---|---|---|---|
| VOL-114-007 | 0 hr | Yes | Yes | Sunita Reddy |
Annexure-2: Sample Processing Log
| Volunteer ID | Start Time | End Time | Processed By | Remarks |
|---|---|---|---|---|
| VOL-114-007 | 10:00 | 10:12 | Rajesh Kumar | None |
Annexure-3: Sample Transfer Log
| Date | Transferred By | Received By | Container ID | Status |
|---|---|---|---|---|
| 17/04/2025 | Ajay Verma | Meena Joshi | BOX-22 | Intact |
Annexure-4: Contamination Incident Report
| Date | Volunteer ID | Description | Root Cause | CAPA |
|---|---|---|---|---|
| 16/04/2025 | VOL-114-005 | Sample mixed with wrong label | Label not double-checked | Staff retraining, checklist revision |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 12/01/2022 | 1.0 | Initial SOP | Regulatory Requirement | QA Head |
| 17/04/2025 | 2.0 | Added checklist annexures and clarified glove and pipette usage | Audit Findings | QA Head |