Standard Operating Procedure for Metabolite Monitoring (Glucose, Lactate, Ammonia) in Bioreactor Operations for Biosimilars

Department	Biosimilars
SOP No.	SOP/BS/081/2025
Supersedes	SOP/BS/081/2022
Page No.	Page 1 of 11
Issue Date	04/05/2025
Effective Date	06/05/2025
Review Date	04/05/2026

1. Purpose

To establish the procedure for monitoring key metabolites such as glucose, lactate, and ammonia in bioreactor operations for biosimilar manufacturing, ensuring optimal cell growth and product yield.

2. Scope

This SOP applies to all bioreactor systems operated for biosimilar production where monitoring of culture metabolites is critical for cell viability, productivity, and media optimization.

3. Responsibilities

• Process Technician: Collect in-process samples and coordinate metabolite analysis.
• QC Analyst: Analyze glucose, lactate, and ammonia using biochemical analyzers or assay kits.
• QA Officer: Verify testing records and investigate out-of-specification results.

4. Accountability

The Bioprocessing Manager is accountable for ensuring timely and accurate metabolite monitoring in compliance with process and GMP guidelines.

5. Procedure

5.1 Sample Collection

1. Draw 5–10 mL of culture fluid using aseptic technique as per SOP/BS/078/2025.
2. Label sample tubes with Batch No., Date, Time, and Sample ID.
3. Transport to QC within 30 minutes using a cold box if required.

5.2 Instrument Setup and Calibration

1. Ensure biochemical analyzer (e.g., YSI, Cedex) is calibrated with appropriate standards.
2. Use fresh reagents for colorimetric assay kits (if applicable).
3. Record instrument calibration details in Annexure-1.

5.3 Glucose Measurement

1. Load 500 µL of sample into analyzer or assay reaction cuvette.
2. Perform enzymatic detection or biosensor-based quantification of glucose.
3. Acceptable range: 1–6 g/L during exponential growth phase.

5.4 Lactate Measurement

1. Use enzymatic kits or analyzer module specific for lactate.
2. Range of concern: >3 g/L may indicate metabolic stress; plan corrective action.

5.5 Ammonia Measurement

1. Use ion-selective electrode or colorimetric method.
2. Range of concern: >1.5 mM could be toxic to cells.

5.6 Documentation and Trending

1. Record all results in Metabolite Monitoring Log (Annexure-2).
2. Plot real-time metabolite trends for process control and decision making.
3. Initiate deviation if values exceed predefined limits.

6. Abbreviations

• QC: Quality Control
• GMP: Good Manufacturing Practice
• YSI: Yellow Springs Instrument (biochemical analyzer)

7. Documents

1. Instrument Calibration Record – Annexure-1
2. Metabolite Monitoring Log – Annexure-2

8. References

• USP <1225> – Validation of Compendial Procedures
• ICH Q6B – Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Instrument Calibration Record

Date	Instrument ID	Parameter	Standard Used	Calibrated By
04/05/2025	YSI-3010	Glucose	2 g/L Glucose Std	Sunita Reddy

Annexure-2: Metabolite Monitoring Log

Date	Time	Batch No.	Glucose (g/L)	Lactate (g/L)	Ammonia (mM)	Tested By
04/05/2025	12:00	BS-081-B03	3.5	1.2	0.9	Rajesh Kumar

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
04/05/2025	2.0	Added ammonia monitoring steps and updated QC log format	Process Enhancement