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Droplet Digital PCR Applications for Cell and Gene Therapy — Unrivaled Precision and Accuracy for Quality Manufacturing

Precise Quantification Without a Reference Standard
(PDF 437 KB)

Quality Control Solutions For Cell And Gene Therapy
(PDF 1.6 MB)
Droplet Digital PCR (ddPCR) provides highly precise absolute quantification of nucleic acid sequences by counting nucleic acid molecules encapsulated in discrete, volumetrically defined water-in-oil droplet partitions. This digital measurement is suitable for the analysis of both in-process samples and final drug products due to the inhibitor tolerant nature of Droplet Digital PCR. This insensitivity to formulation matrices enables the implementation of Droplet Digital PCR throughout the entire manufacturing process. Bio-Rad's ddPCR systems utilize a simple workflow with minimal hands-on time while reducing sample replicates and user-to-user variability.
Droplet Digital PCR is GMP-ready, designed to meet production and Quality Control (QC) environment needs:
- Regulatory edition software to assist with U.S. FDA 21 CFR Part 11 compliance
- Installation qualification/operational qualification (IQ/OQ) service
- Premier service offerings with rapid on-site support
Droplet Digital PCR Tools for Adeno-Associated Virus and Lentivirus Production in Gene Therapy

Adeno Associated Virus: Enabling Genomic Medicine
(PDF 922 KB)
Developing effective and reproducible gene therapies requires the use of sensitive and robust testing methods, such as Droplet Digital PCR, to validate the quality of the therapeutic product. Bio-Rad's portfolio of ddPCR Viral Quantification solutions offers an accurate, precise, and robust method to measure the viral titer in a sample. Customers may also use some of these solutions to perform quality checks on incoming plasmids and conduct biodistribution studies.
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Plasmid Quality
- Vector Backbone Assays
- Gene of Interest Assays
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Viral Titer and Vector Copy Number
- Vector Backbone Assays
- Gene of Interest Assays
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Contaminant Testing
- Mycoplasma Detection
- Residual DNA Supermix
- Host Cell DNA HEK293 Quantification and sizing
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Biodistribution and Patient Monitoring
- Vector Backbone Assays
- Gene of Interest Assays
ddPCR Assays for AAV Viral Titer Quantification
Bio-Rad's Droplet Digital PCR (ddPCR) Assays for AAV viral titer utilize the precision and sensitivity of ddPCR technology to deliver an absolute count of AAV vector genome copies in your sample. These assays can be ordered through the Cell and Gene Therapy Design Engine and come in two varieties:
- Custom ddPCR Cell and Gene Therapy Assays generated for target gene of interest
- Ready-to-order ddPCR Expert Design Assays for common viral vector and plasmid elements
Droplet Digital PCR Tools for CAR-T Development and Monitoring in Cell Therapy
Development, validation, and implementation of robust and accurate methods are vital to test the safety and efficacy of gene-modified cell therapies, such as Chimeric Antigen Receptor T (CAR-T) cells. Droplet Digital PCR offers absolute quantification of transgene copy number in a sample. This method can be used to effectively quantify CAR copy numbers in transfected or transduced T cells or count the number of cells that contain the transgene of interest. This is especially important for transgenes that cannot be detected by antibodies. The ddPCR Whole Cell DNA Workflow is a reproducible and easy way to measure the percentage of edited cells with minimal input cells and can be applied at multiple steps during the cell therapy manufacturing process.
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Vector Copy Number
- Axi-cel Assay
- Axi-cel and Tisa-cel Universal Assay
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Percent Modified Cells
- Whole Cell DNA Workflow
- Axi-cel Assay
- Axi-cel and Tisa-cel Universal Assay
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Contaminant Testing
- Mycoplasma Detection
- Residual DNA Supermix
- Host Cell DNA HEK293 Quantification and sizing
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Biodistribution and Patient Monitoring
- Axi-cel Assay
- Axi-cel and Tisa-cel Universal Assay
The ddPCR Whole Cell DNA Workflow:
- Accurately measure the percentage of modified cells at the DNA level
- Does not require surface expression or cell staining
- Robust and sensitive detection enables low input cell requirement (100–1,000 cells)
- Easy, reproducible workflow and analysis makes it a scalable solution

ddPCR Assays and Resources for CAR-T Cell Therapy
ddPCR Whole Cell DNA Workflow
Purchase the Enhancer Reagent A to enable the ddPCR Whole Cell DNA Workflow and accurately count modified cells.
In-vivo monitoring of CAR-T cells using sensitive Droplet Digital PCR Webinar
Learn about how Dr. Fehse uses ddPCR as a tool to monitor infused CAR-T cells in real-time using samples from patients.
Accurate In-Vivo Quantification of CD19 CAR-T Cells Using Digital PCR
Read about a novel digital PCR assay developed to monitor Tisa-Cel and Axi-cel CAR-T cells in patient samples.
CD19 CAR-T ddPCR Expert Design Assay
Order the CD-19 CAR-T specific assay for the detection of Axi-cel or Tisa-cel transgene DNA as described in Dr. Fehse's research.
Droplet Digital PCR (ddPCR) Is Well Suited for Quantifying Transgene Copy Number
Read about how ddPCR enables you to quantify your CAR T transgene copy number.

Contaminant Testing in Cell and Gene Therapy
Mycoplasma Detection

Droplet Digital PCR Mycoplasma Testing
(PDF 370 KB)
Cell lines and patient samples are prone to outbreaks of various mycoplasma infections; therefore, it is essential to address outbreaks as soon as they occur through robust testing. The Vericheck ddPCR Mycoplasma Detection Kit is a probe-based, highly sensitive and specific mycoplasma detection solution. This kit is designed and validated to meet European, U.S. and Japanese pharmacopoeia requirements. Detect up to 112 mycoplasma species using droplet digital PCR. Utilize the regulatory 21 CFR Part 11 compliant software to easily analyze and report your data.
Vericheck ddPCR Mycoplasma Solution
- Verify mycoplasma presence/absence with absolute quantification
- Reduce variability, plate-to-plate and user-to-user, giving highly reproducible results
- Lower cross reactivity with related species, providing low false positive results.
The Vericheck ddPCR Mycoplasma Detection Kit is now available.
Residual Host DNA Quantification
Residual DNA content is a common impurity in cell and gene therapy manufacturing, and levels must be carefully monitored for lot release. Droplet Digital PCR is a precise and sensitive method for direct quantitation of residual DNA content. Since Droplet Digital PCR does not rely on reaction efficiency for quantitation, it is less prone to sample interference from complex matrices and process intermediates.

ddPCR Supermix for Residual DNA Quantification
(PDF 530 KB)
Droplet Digital PCR provides a highly sensitive method for direct quantification of residual HCD to ensure adherence to the FDA guideline of <100 pg/dose.
ddPCR Host Cell DNA Workflow
- No DNA purification required
- Inhibitor tolerance to in-process low pH and high salt sample matrices
- Optimized supermix free of detectable E. coli, Chinese Hamster Ovary (CHO), mouse, human, and yeast DNA are available
Vericheck ddPCR HEK293 Residual DNA Quantification Kit
Residual DNA from HEK293 lines can harbor tumorigenic genetic sequences or retroviral sequences that could be transmitted through the biotherapeutic to the human recipients. Accurate quantification of HEK293 DNA is essential to produce a safe and appropriate therapeutic dose.

HEK293 Host Cell DNA Residual Testing
(PDF 314 KB)
The Vericheck ddPCR HEK293 Residual DNA Quantification Kit, with a novel ddPCR assay, has been designed to quantify residual HEK293 DNA in biotherapeutics with high specificity and reproducibility, without the need for reference curves.
The Vericheck ddPCR HEK293 Residual DNA Quantification Kit is now available.
Vericheck ddPCR HEK293 Residual DNA Size Kit
Human gene therapy products are produced in immortalized cell lines, most commonly HEK293. Residual DNA from immortalized cell lines can harbor tumorigenic genetic sequences or retroviral sequences that can cause infection. The FDA recommends that manufacturers degrade any residual DNA to a size below that of a functional gene, defined as <200 base pairs. Manufacturers require an inexpensive, accurate, and reliable way of measuring the size of residual DNA, which ddPCR technology can provide.
The Vericheck ddPCR HEK293 Sizing Kit is the first HEK293 specific ddPCR based sizing solution that has been designed, and validated to meet regulatory guidance requirements and capable of measuring HEK293 size without the use of reference curves.
The Vericheck ddPCR HEK293 Residual DNA Size Kit is now available.