Product Overview

Hzymes Biotech has upgraded its host residual DNA detection products, covering multiple cell types such as CHO, E. coli, Vero, HEK293, Pichia pastoris, and mycoplasma. The primer and probe sequences of the kit are from the pharmacopoeia, so you don’t need to do a full set of validation experiments, just need to confirm the method. Developed based on a quantitative PCR method, LODs can reach 0. 003 pg/μL with no cross-reactivity with other DNA, reducing false positives in the assay reaction. Strict production management system, batch-to-batch difference controllable CV< 10%. Provide a complete set of solutions for manual extraction and automatic instrument extraction< /b40>, which can quickly complete the detection within 2 hours and ensure the accuracy of quantitative detection.

Background

Residual host cell DNA is considered a critical process-related impurity in biologics manufacturing. Regulatory guidelines recommend the use of highly sensitive analytical methods to ensure residual DNA levels are effectively controlled.

Because CHO cells are extensively used in the production of therapeutic proteins and antibodies, a validated and pharmacopoeia-based detection method can help streamline regulatory compliance and analytical verification activities.

Intended Use

The CHO DNA Assay Kit (USP) is intended for the quantitative determination of residual CHO host cell DNA in biological products using TaqMan probe-based qPCR technology.

The assay is suitable for:

• Recombinant proteins

• Monoclonal antibodies

• Vaccines

• Cell culture-derived biologics

Primer and probe sequences are designed according to USP-referenced methods for reliable residual DNA analysis.

Key Features

USP-Based Assay Design

Primer and probe sequences are designed according to the United States Pharmacopeia (USP) methodology.

Simplified Method Verification

Pharmacopoeia-based assay design may reduce the effort required for method establishment and verification.

Ultra-Sensitive Detection

Detect residual CHO DNA down to 0.003 pg/μL.

National Standard-Calibrated Quantification

Standards are calibrated against national reference materials to support measurement accuracy.

High Specificity

No cross-reactivity with non-target DNA, improving assay confidence and reducing false positives.

Reproducible Performance

Manufactured under strict quality control procedures with batch-to-batch variation controlled below 10%.

Applications

USP-Based Residual DNA Analysis

Detection and quantification of residual CHO DNA using a pharmacopoeia-referenced assay design.

Regulatory and Quality Control Testing

Suitable for analytical laboratories requiring standardized residual DNA testing methods.

Biopharmaceutical Process Monitoring

Monitor host cell DNA removal throughout purification and manufacturing processes.

Final Product Release Testing

Support residual DNA testing in therapeutic proteins, antibodies, and vaccines.

Performance Data

USP-Derived Primer and Probe Sequences

The standards in the CHO HCD kit were calibrated using the national CHO DNA standard, and the standard from different manufacturers was detected with the same kit, and the deviation of the measured value of the new enzyme standard was less than 5%.

National Standard Calibration

Standards are calibrated using national CHO DNA reference standards to improve measurement accuracy.

High Sensitivity and Specificity

Validated performance demonstrates excellent sensitivity, specificity, repeatability, and precision.

Consistency with Real Sample Testing

Results obtained from real biopharmaceutical samples show strong agreement and reliable quantification performance.

Robust Manufacturing Quality

The finished product of the extraction reagent is assembled and used directly, without the need to prepare reagents separately, and the whole set is stored stably at room temperature. Fully automated instrument extraction with pre-packaged kits for flexible on-demand access.

FAQ

Why is the DNA recovery or qPCR signal lower than expected?

Possible Cause 1: High protein or impurity load in the sample

Complex sample matrices may inhibit efficient DNA release or amplification.
Optimize sample pretreatment by increasing Proteinase K concentration and extending digestion time to improve extraction efficiency.

Possible Cause 2: Magnetic bead loss during extraction steps

Improper handling during washing may cause bead loss and reduce DNA yield.
Ensure beads are fully resuspended by gently flicking the tube or briefly vortexing to prevent loss during magnetic separation steps.

Possible Cause 3: Improper sample pH conditions

Non-neutral pH may reduce binding efficiency in magnetic bead-based extraction.
Adjust sample pH to a neutral range before extraction.

Possible Cause 4: Incomplete elution mixing

Poor mixing between elution buffer and magnetic beads reduces DNA recovery.
Vortex thoroughly after adding elution buffer. If beads remain attached to tube walls, incubate at 60°C for 2 minutes and repeat mixing.

Why is there variability in CHO DNA quantification results?

Possible Cause 1: Improper storage of magnetic beads

Storage at -18°C or below may negatively impact bead performance.
Store magnetic beads at 2–8°C and avoid freezing to ensure consistent assay performance.

Possible Cause 2: Pipetting inaccuracy during sample handling

Inconsistent liquid handling leads to variability in results.
Use calibrated pipettes and low-retention filtered tips to improve precision and reproducibility.

Possible Cause 3: Magnetic bead carryover into eluate

Residual beads in eluate may interfere with downstream qPCR quantification.
After elution, centrifuge and carefully transfer the supernatant without disturbing magnetic beads.