Biopharma Quality Control Solutions

Residual DNA · Host Cell Protein · Process Residuals · Microbial Safety

As biologics expand across cell and gene therapy, antibody drugs, recombinant proteins, mRNA therapeutics, and vaccines, quality control requirements are becoming increasingly stringent.

Yeasen provides integrated QC solutions covering sample preparation, residual DNA detection, HCP and residual enzyme analysis, process-related impurity testing, and biological safety testing. Built on in-house technologies and an ISO 13485 quality system, our solutions support critical QC checkpoints from upstream processing to final product release.

2. QC Solutions Across Biopharma Applications

Different modalities share many of the same QC targets, while specific testing requirements depend on the host cell, manufacturing process, and product type.

Explore QC solutions across five major biopharma application

2.1 Cell Therapy

From cell expansion and genetic modification to final product release, QC focuses on residual host-cell components, process-related impurities, microbial contamination, and genetic safety. 

Flow chart copy:  Stage 1: Plasmid Construction & Production  →  Stage 2: Lentiviral Vector Production  →  Stage 3: T Cell Isolation · Activation · Transduction  →  Stage 4: CAR-T Cell Expansion & Harvest  →  Stage 5: Formulation & Release Testing

Primary QC Solutions

HCD (HEK293 · plasmid · E. coli) · HCP (HEK293) · Biological risk & CGT safety (RCL · RCR · CAR/TCR copy number · mycoplasma · endotoxin)

2.2 Gene Therapy

AAV · Lentivirus · Adenovirus · Oncolytic Virus

Gene therapy manufacturing requires control of host-cell residues, process-related impurities, and replication-competent viral contaminants throughout vector production.

Figure 2 — Gene Therapy process flow.

Flow chart copy:  Stage 1: Plasmid Construction & Production  →  Stage 2: Viral Packaging & Production  →  Stage 3: Virus Purification (Lysis · Nuclease · Chromatography)  →  Stage 4: Harvest, Formulation & Release

Primary QC Solutions

HCD (HEK293 · Sf9/baculovirus · E. coli) · Process residuals (nuclease) · Biological risk & CGT safety (rcAAV2 · RCA · RCL · RCR)

2.3 Antibody Drugs & Recombinant Proteins

Mammalian · Yeast · Prokaryotic Expression Systems

QC requirements vary with the expression system and downstream process, with key targets including residual host-cell DNA, HCP, and process-related reagents.

Figure 3 — Antibody Drugs & Recombinant Proteins process flow.

Flow chart copy:  Stage 1: Cell Bank Establishment & Characterisation  →  Stage 2: Cell Culture (Mammalian / Yeast / Prokaryotic Systems)  →  Stage 3: Harvest & Purification  →  Stage 4: Formulation & Release Testing

Primary QC Solutions

HCD (CHO · E. coli · yeast) · HCP (CHO · E. coli · Pichia) · Process residuals (Protein A · BSA · nuclease)

2.4 mRNA Vaccines & Therapeutics

From plasmid template to LNP-encapsulated drug product release. mRNA manufacturing introduces process-specific QC requirements, including residual DNA, process enzymes, and dsRNA generated during RNA synthesis.

Figure 4 — mRNA Vaccines & Therapeutics process flow.

Flow chart copy:  Stage 1: Plasmid Template Production  →  Stage 2: In Vitro Transcription (IVT)  →  Stage 3: Capping, Tailing & Purification  →  Stage 4: LNP Encapsulation & Formulation  →  Stage 5: Drug Product Release Testing

Primary QC Solutions

HCD (E. coli · plasmid DNA residue) · Process residuals (T7 RNA polymerase · capping enzyme · RNase inhibitor · dsRNA)

2.5 Vaccines

Vero · MDCK · CHO · Yeast and Other Platforms
Vaccine manufacturing requires control of residual host-cell components, process-related impurities, and biological safety throughout production.

Figure 5 — Vaccines process flow (four stages). Recommended QC products at each stage: see the Stage Product List workbook.

Flow chart copy:  Stage 1: Cell Substrate Preparation & Characterisation  →  Stage 2: Seed Lot · Culture & Harvest  →  Stage 3: Purification & Nucleic Acid Clearance  →  Stage 4: Formulation & Release Testing

Primary QC Solutions

HCD (Vero · MDCK · CHO · yeast) · HCP (CHO) · Biological risk & CGT safety (mycoplasma · endotoxin · cell species Identification)

3. Product Coverage Across Applications

Yeasen QC portfolio is organized around key testing needs rather than individual modalities, making it easier to select the right solution based on your host cell, process step, and QC target.

Table 1. Product series coverage by application

● Core solution    ○ Applicable / selected products    — Not required

4.  Product Solution — Series Highlights

4.1 Host Cell Residual DNA (HCD) Detection

qPCR-based residual DNA quantification across major expression systems

Yeasen HCD detection solutions quantify residual host-cell DNA from major expression systems, including CHO, HEK293, E. coli, Vero, MDCK, human cells, yeast, and insect cells, with matched magnetic-bead sample preparation and residual DNA size analysis.

Feature	Performance
High Sensitivity	Detection limit down to 0.5 fg/µL
High Precision	Repeatability CV < 10%; intermediate precision < 15%
High Specificity	Host-specific primers show no cross-reactivity between cell lines and no interference from plasmid DNA
Reliable Recovery	Matched magnetic-bead preparation achieves 70–130% host-cell DNA recovery
Fast Time-to-Result	Complete workflow from lysis to qPCR result within 3 hours
Residual DNA Size Analysis	Quantifies both residual DNA amount and fragment-size distribution to support DNA clearance assessment

Series Coverage

10 host cell lines · Plasmid DNA residue · E. coli host cell RNA residue · 4 residual DNA size analysis kits

High Sensitivity

High Precision

A HEK293 DNA standard sample at 30 pg/μL was tested 10 times. The CV was <15%, meeting the repeatability requirement.

Replicate No.	1	2	3	4	5	6	7	8	9	10	Mean	CV
Measured Value (pg/μL)	29.51	30.02	30.13	30.16	27.99	31.01	31.05	30.95	31.02	29.86	30.17	3.15%

A Vero DNA standard sample at 3 pg/μL was tested 10 times. The CV was <15%, meeting the repeatability requirement.

Replicate No.	1	2	3	4	5	6	7	8	9	10	Mean	CV
Measured Value (pg/μL)	3.10	3.49	3.61	3.55	3.75	3.84	3.54	3.64	3.45	3.48	3.57	5.72%

A E. coli DNA standard sample at 3 pg/μL was tested 10 times. The CV was <15%, meeting the repeatability requirement.

Replicate #	1	2	3	4	5	6	7	8	9	10	Mean	CV (%)
Measured (pg/μL)	3.16	2.87	2.97	2.86	2.81	2.97	3.14	3.21	3.14	3.10	3.02	4.78
Recovery Ratio (%)	105.33	95.67	99.00	95.33	93.67	99.00	104.67	107.00	104.67	103.33	102.17	—

 

High Specificity

Figure 2. Interference Test Results(E.Coli)

Interference from genomic DNA commonly used in biopharmaceutical production (HEK293, Vero, CHO) was evaluated. No interference was observed—the amplification curves of interference groups overlapped with those of the control group.

Reliable Recovery

Spiked Recovery in Blank Matrix-E.coli Host Cell DNA Residue Detection Kit

Samples spiked at high (300 pg/μL), medium (3 pg/μL), and low (30 fg/μL) concentrations of E. coli DNA were processed using the magnetic bead-based DNA extraction kit (two independent extractions per sample, each with three technical replicates). Recovery rates for all concentrations fell within 70–130%, with CVs <20%.

Sample Type	Theoretical Concentration	Mean Extraction 1	Mean Extraction 2	Mean Measured Concentration	CV (%)	Recovery (%)
Blank	—	—	—	—	—	—
Recovery Sample 1	300 pg/μL	250.56 pg/μL	262.11 pg/μL	256.33 pg/μL	4.41	85.44
Recovery Sample 2	3 pg/μL	2.29 pg/μL	2.56 pg/μL	2.42 pg/μL	7.09	80.77
Recovery Sample 3	30 fg/μL	33.62 fg/μL	32.61 fg/μL	33.12 fg/μL	14.28	110.39

4.2 Host Cell Protein (HCP) & Residual Enzyme ELISA

Sandwich ELISA for host cell proteins and process-related residual enzymes

Yeasen provides HCP ELISA solutions for CHO, HEK293, E. coli, and Pichia pastoris, together with ELISA kits for residual enzymes used throughout biologics and mRNA manufacturing.

Key Highlights

Feature	Performance
High Sensitivity	LOQ down to the single-digit ng/mL level
High Specificity	Antibodies raised against matched host cell lines
One-Step Option	One-step CHO HCP ELISA format for reduced hands-on time
Regulatory Alignment	Developed and validated in accordance with ChP, USP, EP and ICH Q2(R2) requirements
In-house Development	Capture antibodies, detection antibodies and reference standards developed and manufactured in house
Lot-to-Lot Control	Controlled production processes and traceable quality documentation

Series Coverage: CHO HCP · HEK293 HCP · E. coli HCP · Pichia pastoris HCP

4.3 Process-related Impurity & Residual Reagent Control

Targeted testing for process-specific residuals

Process-related impurities are determined by the manufacturing process and may originate from purification, cleavage, enzymatic modification, or formulation steps.

Yeasen provides ELISA and activity-based assays for a broad range of process residuals.

Feature	Coverage
Broad Process Coverage	Protein A · BSA · Enterokinase · Nuclease · T7 RNA Polymerase · Inorganic Pyrophosphatase · RNase Inhibitor · Vaccinia Capping Enzyme
Nuclease Residual Testing	Assays for UCF.ME™ UltraNuclease and Salt Active UltraNuclease
Enzyme Activity Verification	DNase and RNase activity assays help verify functional clearance
mRNA-specific QC	dsRNA ELISA and residual enzyme testing for key mRNA manufacturing steps
Process-matched Testing	Assays matched to the enzymes used in production for improved process traceability

Series Coverage

Protein A · BSA · Enterokinase · UltraNuclease · Salt Active UltraNuclease · T7 RNA Polymerase · Inorganic Pyrophosphatase · RNase Inhibitor · Vaccinia Capping Enzyme · dsRNA · DNase/RNase Activity · Reverse Transcriptase Activity

4.4 Biological Risk & CGT Safety Testing

Safety testing for microbial contamination and genetic risks

Yeasen provides testing solutions for critical biological risks in cell and gene therapy manufacturing, covering endotoxin, mycoplasma, replication-competent viruses, vector genomes, and cell substrate identity.

Feature	Performance
Endotoxin Detection	Recombinant Factor C kinetic assay as an animal-free alternative to LAL
Rapid Mycoplasma Testing	Real-time qPCR method validated against EP 2.6.7, USP 63 and JP G3
Replication-Competent Virus Testing	RCL · RCR · rcAAV2 · RCA detection
Vector Genome Quantification	CAR/TCR copy number and lentivirus physical titer qPCR
Cell Substrate Identification	Multiplex PCR-based cell species identification
Vector Process Monitoring	HIV-1 p24 ELISA for lentiviral vector production

Series Coverage: Recombinant Factor C Endotoxin · MycAway™ Mycoplasma qPCR · RCL · RCR · rcAAV2 · RCA · SV40 LTA & E1A · CAR/TCR Copy Number · Lentivirus Physical Titer · Cell Species Identification · HIV-1 p24

5. Performance Validation Report Summary

HCD Detection Products

HCP & Process Residual Products

6.  FAQ

Q1. How do I choose the right QC solution for my product?

Most QC targets are determined by the host cell or manufacturing process rather than the final product type. Select the relevant modality first, then identify the host cell line and process step to determine the appropriate QC series.

Q2. Which regulatory requirements do the kits support?

The kits are developed and validated under an ISO 13485 quality system, with testing aligned with relevant ChP, USP, EP and ICH Q2(R2) requirements. Performance validation reports are available for the listed products.

Q3. How sensitive are the residual DNA detection kits?

Detection limits reach 0.5 fg/µL, with standard curves traceable to national reference standards and CV < 5%.

Q4. How specific are the HCP ELISA kits?

The kits use antibodies raised against matched host cell lines. The LOQ reaches the single-digit ng/mL level.

Q5. Are validation reports and audit documentation available?

Yes. Performance validation reports are available for the listed products. CoA, lot traceability, and method validation documentation are available on request.

Q6. How is residual DNA prepared before qPCR?

Matched Hieff™ magnetic-bead sample preparation kits can be used to prepare qPCR-ready DNA. The workflow from lysis to qPCR-ready DNA can be completed within 3 hours, with 16 / 48 / 96-channel automated extraction options.

Q7. Can these solutions support IND / BLA submissions?

The products have been used in IND filings accepted by the China CDE and U.S. FDA, supporting China–US dual filing strategies.

Q8. How is lot-to-lot consistency controlled?

Key components, including capture antibodies, detection antibodies, reference standards, and selected enzymes, are developed and manufactured in house, with controlled production and lot traceability.