Standard Operating Procedure for Tank-to-Tank Transfer of Cultures in Biosimilar Manufacturing

Department	Biosimilars
SOP No.	SOP/BS/109/2025
Supersedes	SOP/BS/109/2022
Page No.	Page 1 of 12
Issue Date	04/05/2025
Effective Date	06/05/2025
Review Date	04/05/2026

1. Purpose

To define the procedure for aseptic and controlled transfer of cell culture from one tank to another (e.g., seed to seed, or seed to production bioreactor) during upstream biosimilar manufacturing, ensuring sterility and product integrity.

2. Scope

This SOP applies to all tank-to-tank culture transfers within the biosimilar upstream suite using peristaltic pumps, transfer bags, or direct sterile tubing connections.

3. Responsibilities

• Production Operator: Execute tank transfer as per protocol and document operations in real time.
• Production Supervisor: Review and approve transfer setup and monitor transfer completion.
• Engineering: Ensure pump calibration and tubing integrity prior to transfer.

4. Accountability

The Head of Production is accountable for ensuring sterile and efficient transfer of culture material without contamination risk or product loss.

5. Procedure

5.1 Pre-Transfer Preparation

1. Verify source and destination tanks are labeled, cleaned, sterilized, and pressure tested.
2. Ensure pre-use integrity of the seed and recipient bioreactor (temperature, DO, pressure).
3. Check seed culture viability (≥ 90%) and log in Annexure-1.

5.2 Connection Setup

1. Use sterile single-use transfer tubing or sanitized stainless-steel transfer lines.
2. Secure all tubing with clamps and aseptic connectors (e.g., AseptiQuik, CPC fittings).
3. Confirm pump type (peristaltic recommended) is cleaned and tubing loaded correctly.

5.3 Transfer Execution

1. Start peristaltic pump at a flow rate suitable for vessel size (e.g., 1 L/min for 200 L).
2. Monitor for:
   • Air entrapment
   • Foaming
   • Backflow
3. Adjust speed and pause if needed to prevent culture shearing or foam overflow.
4. Complete transfer within 30–60 minutes for standard batches.

5.4 Post-Transfer Actions

1. Clamp off tubing, disconnect using sterile scissors or welders.
2. Flush lines with sterile WFI or air if protocol requires.
3. Start mixing, temperature ramping, and DO stabilization in recipient tank.

5.5 Documentation

1. Complete Annexure-2: Transfer Log Sheet with volume, timings, and signatures.
2. Notify QA and submit transfer batch record for review.

6. Abbreviations

• DO: Dissolved Oxygen
• WFI: Water for Injection
• QA: Quality Assurance

7. Documents

1. Tank Transfer Pre-Check Record – Annexure-1
2. Transfer Log Sheet – Annexure-2

8. References

• WHO TRS 999 – Guidelines on Biopharmaceutical Manufacturing
• FDA Guidance on Aseptic Processing (2004)

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Tank Transfer Pre-Check Record

Parameter	Status	Checked By	Date
Source Tank Sanitized	Yes	Sunita Reddy	04/05/2025
Recipient Tank Calibrated	Yes	Ajay Verma	04/05/2025

Annexure-2: Transfer Log Sheet

Date	From Tank	To Tank	Volume Transferred (L)	Start–End Time	Performed By
04/05/2025	Seed-BR-02	Prod-BR-10	100	10:00–10:50	Sunita Reddy

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
04/05/2025	2.0	Included closed-loop transfer precautions and line flushing protocol	Process improvement