Must-Read for Biopharma Companies

Background

In the biopharmaceutical industry, CHO (Chinese Hamster Ovary) cells are the most widely used expression system for the production of monoclonal antibodies, antibody-drug conjugates (ADCs), interferons, vaccines, and more.

However, due to the biological production processes, residual Host Cell DNA (HCD) from CHO cells inevitably remains in the final products.

Such residual DNA poses potential risks, including immunogenicity, infectivity, and oncogenicity after entering the human body.

Thus, residual DNA testing is a mandatory compliance requirement in the quality control of biopharmaceuticals.

With the 2025 Chinese Pharmacopoeia (ChP 2025) implementation approaching, the standards for HCD detection are being further upgraded.

How can pharmaceutical companies quickly adapt to the new regulations while ensuring reliable and efficient testing results?

This article offers an in-depth analysis of the regulatory updates and detection challenges for CHO HCD.

1. Key Changes in the 2025 Chinese Pharmacopoeia

Shift Toward qPCR for HCD Detection

The 2025 ChP further strengthens HCD detection requirements for biologics, especially CHO cell-expressed recombinant protein products such as monoclonal antibodies and ADCs. Major updates include:

• Expanded Scope of HCD Testing

Multiple monoclonal antibody drugs, such as Trastuzumab, Infliximab, Adalimumab, Bevacizumab, and Rituximab, as well as vaccines like the inactivated Sabin strain polio vaccine, are newly required to use the General Chapter 3407 Third Method (Quantitative PCR, qPCR) for HCD detection.

• Inclusion of ADCs Under Regulatory Control

ADC products must now comply with both the general chapter for monoclonal antibodies and related monographs, with mandatory residual DNA testing.

• Stricter Residual Limits

For example, Bevacizumab and Rituximab require residual HCD ≤10 pg/mg, and some growth hormone products require ≤1.5 ng/mg.

• qPCR as the Preferred Method

While the 2020 Pharmacopoeia accepted hybridization, fluorescent dye staining, and qPCR methods, the 2025 update designates qPCR as the mainstream approach for multiple new drug categories.

2. HCD Detection Challenges Across Different Biologic Types

Vaccines

• Production Process:

CHO cells express viral-like particles (VLPs) or recombinant antigens, followed by TFF concentration and multiple chromatography steps (e.g., anion exchange, size exclusion) to remove impurities.

• Challenge:

High sugar content (e.g., sucrose, trehalose) in vaccine formulations can increase sample viscosity, hinder DNA release, and interfere with fluorescent signal detection.

Monoclonal Antibodies (mAbs)

• Production Process:

CHO cells secrete antibodies into the culture medium, purified through Protein A affinity and ion exchange chromatography, followed by virus removal steps.

• Challenge:

High protein concentration (up to 100–200 mg/mL) can cause protein-DNA complexation, aggregation, or high solution viscosity, compromising DNA recovery and test accuracy.

Antibody-Drug Conjugates (ADCs)

• Production Process:

Purified antibodies are conjugated with cytotoxic payloads via linkers under specific pH conditions (pH 4.0–8.0), followed by hydrophobic interaction chromatography (HIC) and buffer exchange.

• Challenge:

Extreme pH conditions during conjugation may fragment DNA or destabilize qPCR reagents, impacting detection results.

3. Hzymes' Comprehensive Solution for HCD Detection

Real-World Proven Performance

In response to the upgraded regulatory landscape, Hzymes offers specialized solutions for compliant and efficient HCD testing across vaccines, monoclonal antibodies, recombinant proteins, and ADCs.

Product Offerings

• Host Cell DNA Sample Preparation Kits

oAvailable for both manual and automated magnetic bead extraction.

oManual extraction completed in 2 hours; automated process within 1.5 hours with <30 minutes hands-on time.

• CHO Host Cell DNA Detection Kits

oPre-designed with official Pharmacopoeia sequences.
oNo additional assay validation needed, saving significant development time.

4. Product Highlights

Core Advantages

• Accurate Quantification

Standards, primers, and probes strictly match official pharmacopoeia sequences, ensuring high-precision quantification.

• Stable and Reliable Results

Validated with diverse complex samples (high sugar, high protein, extreme pH), achieving consistent DNA recovery rates between 70%-130%.

• Fast and Easy Operation

Flexible manual or automated extraction options reduce labor and time costs.

• Outstanding Service

Comprehensive technical support and customized solutions.

Data Highlights

• High Purity and Precision

oDNA standards with <5% concentration deviation.

oDirect match to pharmacopoeia specifications for seamless regulatory submissions.

• Excellent Sample Stability

oPasses freeze-thaw testing (5 cycles), heat acceleration at 37°C for 7 days, and long-term storage at –20°C for 24 months.

• High Sensitivity and Compatibility

oDetection limit as low as 0.5 fg/μL.
oCompatible with major qPCR platforms (ABI, BioRad, Roche, etc.).

Conclusion

As regulatory standards tighten with the release of the 2025 Chinese Pharmacopoeia, pharmaceutical companies must proactively optimize their CHO Host Cell DNA detection strategies to ensure compliance and product safety.

Hzymes' HCD Detection Solutions empower biopharma manufacturers to achieve stable, accurate, and rapid testing results, significantly reducing regulatory risks and accelerating product commercialization.