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 (HCD) is a critical impurity monitored during biopharmaceutical manufacturing. Regulatory agencies require manufacturers to control and quantify residual DNA to ensure product safety and consistency.

As CHO cells are the most widely used mammalian expression system for biologics production, sensitive and accurate detection of residual CHO DNA is essential throughout process development, purification validation, and final product release testing.

Intended Use

The CHO DNA Assay Kit is intended for the quantitative determination of residual CHO host cell DNA in biological products, including:

• Recombinant proteins

• Monoclonal antibodies

• Vaccines

• Cell culture-derived biopharmaceuticals

The assay is based on quantitative PCR (qPCR) using TaqMan fluorescent probes and is designed to provide rapid, sensitive, and reproducible CHO DNA quantification.

Key Features

High Sensitivity Detection

Detect residual CHO DNA at sub-picogram levels with an LOD as low as 0.003 pg/μL.

Excellent Specificity

Designed to minimize non-specific amplification and cross-reactivity, helping reduce false-positive results.

Reliable Quantification

Strict manufacturing controls ensure lot-to-lot consistency with batch variation controlled at CV <10%.

Fast Workflow

Complete residual DNA testing within approximately 2 hours when combined with compatible extraction solutions.

Flexible Sample Preparation

Supports both manual and automated DNA extraction workflows for different laboratory requirements.

Ready-to-Use Reagents

Convenient reagent format reduces preparation time and simplifies routine testing.

Applications

Residual CHO DNA Testing

Quantitative detection of residual CHO host cell DNA in biologics manufacturing workflows.

Process Development and Validation

Monitor host cell DNA clearance during downstream purification and process optimization.

Quality Control Testing

Support routine quality control and batch release testing of biopharmaceutical products.

Vaccine and Recombinant Protein Manufacturing

Suitable for residual DNA analysis in vaccines, therapeutic proteins, and antibody products produced using CHO expression systems.

Performance Data

The standard products are calibrated by the national standard products

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%.

The primer probe sequences for HCDs of CHO, Vero, E. coli, and yeast are from pharmacopoeia

High sensitivity, specificity, repeatability, precision

No detectable cross-reactivity with non-target DNA under validated assay conditions.

Consistent Results with Real Samples

Performance has been verified using actual biopharmaceutical samples, showing reliable quantitative results.

Simple and convenient

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 detection signal low?

Possible Cause 1: Excessive protein or impurities in the sample

High protein content or complex matrices may inhibit extraction efficiency or PCR amplification.

It is recommended to optimize sample pretreatment and appropriately increase Proteinase K dosage and digestion time to improve DNA release efficiency.

Possible Cause 2: Loss of magnetic beads during extraction or washing steps

Magnetic beads may aggregate at the bottom of the tube during washing, leading to loss.

Gently flick the tube or briefly resuspend the beads to ensure they remain properly positioned on the magnetic rack and reduce bead loss.

Possible Cause 3: Inappropriate sample pH

Strongly acidic or basic conditions may affect DNA binding efficiency.
Adjust sample pH to a neutral range before starting the extraction process.

Possible Cause 4: Incomplete mixing of elution buffer and magnetic beads

Poor resuspension can reduce DNA elution efficiency.
After adding elution buffer, vortex thoroughly to fully resuspend magnetic beads. If beads remain attached to tube walls, briefly incubate at 60°C for 2 minutes and vortex again.

Q2: Why are CHO DNA quantification results inconsistent between runs?

Possible Cause 1: Improper storage of magnetic beads

Storing magnetic beads at -18°C or lower may reduce performance.
Recommended storage condition is 2–8°C, and freezing should be avoided.

Possible Cause 2: Inaccurate pipetting volume

Variations in sample or elution buffer volume can affect reproducibility.
Calibrate pipettes regularly and use low-retention filtered tips to improve accuracy and reduce sample loss.

Possible Cause 3: Carryover of magnetic beads into eluate

Residual beads in the supernatant may interfere with downstream qPCR results.
After elution, centrifuge briefly and carefully transfer the supernatant without disturbing any remaining beads.