QIAcuity Residual DNA Quantification and Sizing Kits

For quantification and sizing of host cell DNA with higher accuracy and precision using the QIAcuity Digital PCR System

S_1262_4_LS_dPCR_QIAcuity_HEK293resDNA_Quant

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QIAcuity HEK293 resDNA Quant Kit (96)

Cat no. / ID.   250224

For 96 reactions: QIAcuity HEK293 resDNA Quant Mastermix (4x) lyophilized, 1x Positive Control, 1x Internal Control, 3x RNAse-Free Water
Kit
resDNA Quant
resDNA Quant Standard
HEK293 resDNA Sizing
Cell type
HEK293
CHO
E. coli
QIAcuity Residual DNA Quantification and Sizing Kits are intended for molecular biology applications. These products are not intended for the diagnosis, prevention, or treatment of a disease.

✓ 24/7 automatic processing of online orders

✓ Knowledgeable and professional Product & Technical Support

✓ Fast and reliable (re)-ordering

Features

  • QIAcuity resDNA Quant Kits enable accurate detection of residual host-cell DNA from E. coli, CHO and HEK293 cells down to low femtogram levels
  • QIAcuity HEK293 resDNA Sizing Kit is used for precise measurement of both the amount and fragment size distribution of host cell DNA and can be optionally multiplexed with oncogenes (e.g., E1A, E1B or SV40 for HEK293T) 
  • A multi-copy target assay that detects and quantifies highly fragmented host cell DNA
  • Enables host cell DNA detection in both extracted and unextracted samples
  • Kits include internal and positive controls and are optimized for the QIAcuity dPCR platform

Product Details

Host cell DNA contamination in products such as vaccines, drugs and other biopharmaceuticals imposes great health risks. Therefore, its safe limits are tightly regulated by agencies such as the FDA and WHO. Clear guidelines for the upper limits of residual DNA are established based on the nature of drug administration, infectivity and oncogenicity of the contaminating cell DNA. For instance, parenteral administration of non-tumorigenic cell DNA should be limited to 10 ng/dose and a maximum length of 200 bp, whereas less than 100 µg/dose of residual DNA is recommended by WHO for orally administered vaccines.  

Detection of such contaminations requires highly sensitive and accurate measurements of the extremely low amounts of specific host cell DNA present in the products. 

Digital PCR is the preferred method for residual DNA (resDNA) quantification. This is due to its unmatched sensitivity and accuracy, especially at trace levels of contamination compared to other detection methods such as qPCR. QIAcuity Residual DNA Quantification Kits provide the accurate and precise detection of Escherichia coli (E. coli), Chinese Hamster Ovary (CHO) and Human Embryonic Kidney 293 (HEK293) host cell DNA. The QIAcuity HEK293 resDNA Sizing Kit allows quantification and fragment size determination to meet guidelines for residual DNA size (<200 bp). This kit also allows for multiplexing with oncogene targets like E1A (Geneglobe ID DMA00938), E1B (GeneGlobe ID DMA01000) or SV40 (GeneGlobe ID DMA00936) for added safety testing flexibility. 

The QIAcuity resDNA Quant Standard Kits are dPCR-verified absolute quantification standards that can be used in combination with resDNA Quant and Sizing Kits for validation of quantitation accuracy or bridging studies. 

Performance

The QIAcuity Residual DNA Quantification Kits provide accurate CHO, E. coli and HEK293 residual DNA quantification results with or without extraction, even in the presence of PCR contaminants or other inhibitory reagents. The assays are multicopy target assays that accurately determine even very low amounts highly fragmented residual host cell DNA. QIAcuity HEK293 resDNA Sizing Kit targets a proprietary multicopy locus, enabling sensitive detection and sizing of HEK293 or human residual DNA via two amplicons (short with less than 200 bp, and long with more than 200 bp). This allows for precise quantification and assessment of DNA size distribution in a single reaction.

  

Assay Target Copy Number Amplicon Size Conversion Factor cp/µL to fg/µL
QIAcuity E. coli resDNA Quant Kit 7 <200 0.35
QIAcuity CHO resDNA Quant Kit ~ 1 million, undefined (repeated element) <100 0.28
QIAcuity HEK293 resDNA Quant Kit ~ 1 million, undefined (repeated element) <100 1.54
QIAcuity HEK293 resDNA Sizing Kit > 20 copies per genome Short Amplicon (~83 bp) 0.129
Long Amplicon (~345 bp) 0.143

Digital PCR provides higher sensitivity of detection at a lower template input range in comparison to qPCR and therefore enables a more robust application.

QIAcuity E. coli resDNA Quant Kit detects as low as 5 fg of residual DNA in a single reaction

Loading amount per reaction (fg/rxn) E. coli Standard (copies/µL) Internal Control (copies/µL)*
50000 2949.7 99.9
5000 291.6 91.7
500 27.6 91.4
50 2.8 93.2
25 1.46 92.5
5 0.45 90.6
NTC 0 98.9

*100 copies/µL expected for Internal Control

QIAcuity CHO resDNA Quant Kit detects as low as 5 fg of residual DNA in a single reaction

Loading amount per reaction (fg/rxn) CHO Standard (copies/µL) Internal Control (copies/µL)*
50000 4939.3     108.7
5000 508.3     104.9
500 50.2     97.6
50 4.7 99.5
25 2.6 101.3
5 0.6 100.4
NTC 0 104.7

*100 copies/µL expected for Internal Control

QIAcuity HEK293 resDNA Quant Kit detects as low as 50 fg of residual DNA in a single reaction

Loading amount per reaction (fg/rxn) HEK293 Standard (copies/µL) Internal Control (copies/µL)*
50000 1104.9 96.6
5000 104.5 92.5
500 8.83 92.4
50 0.99 94.4
NTC 0 96.2

*100 copies/µL expected for Internal Control

The kits work in conjunction with the QIAcuity Digital PCR System and QIAcuity Nanoplates, offering an end-to-end fast dPCR workflow comparable to qPCR, but delivering absolute quantification of resDNA in your sample without the need for standard curves. The kits have been designed according to the requirements of bioprocess manufacturing and QC.

Principle

The principle of the dPCR reaction in the nanoplates is described here.

Using QIAcuity digital PCR for host cell DNA monitoring improves the LOD/LOQ through partitioning of the bulk sample with the help of QIAcuity Nanoplate 26k. Partitioning increases the effective concentration of the target, allowing a small amount of host cell DNA to be captured and measured with higher accuracy and precision. The ability to load high template input amounts in the QIAcuity Nanoplate 26k combined with an increased number of partitions is one of the reasons for the higher accuracy precision and reproducibility residual host cell DNA detection.

Procedure

The sample or extracted template DNA is added to the reaction mix together with the internal amplification control in a standard PCR plate. The reactions are transferred to a Nanoplate and target DNA concentration (copies/µL) is measured by absolute quantification on the QIAcuity System. Copies/µL are converted to fg/µL using the provided conversion factor.

Applications

The QIAcuity Residual DNA Quantification and Sizing Kits are optimized for the highly precise host cell DNA monitoring in complex bioprocess intermediates as well as final products.

Supporting data and figures

FAQ

Is DNA extraction from the samples needed?

No. DNA extraction is not required. However, if the samples contain high levels of PCR inhibitors or high protein concentration, DNA extraction is recommended for accurate quantification/sizing of residual DNA impurities.

FAQ-3873
Which extraction kits are recommended?

Recommended extraction kits compatible with QIAcuity Residual DNA Quantification Kits and QIAcuity Residual DNA Sizing Kit include QIAamp DNA Mini Kit, QIAamp UCP DNA Micro Kits, QIAamp HMW MagAttract Kits, QIAsymphony DSP Kits, QIAsymphony Certal Kits, DNeasy Blood & Tissue Kits, and QIAprep Spin Maxi, Midi, and Miniprep Kits.

FAQ-3874
Is restriction enzyme digestion required?

Restriction digestion of the templates is required when the template length exceeds 20 kb for a better distribution of templates within the nanoplate partitions. Recommended restriction enzymes can be found in the handbook and quick-start protocols.

FAQ-3875
dPCR results are in copies per microliter. How do I calculate host cell DNA impurities in femtogram per microliter or picogram per microliter?

The conversion factors from copies/µL to fg/µL or pg/µL for each target assay are provided in corresponding quick-start protocols and handbooks.

FAQ-3876
My samples are highly fragmented. Is the dPCR result for resDNA quantification accurate?

ResDNA Quant Kit (E. coli, CHO, and HEK293) assays are multicopy target assays that ensure quantification of  resDNA unaffected by the fragmentation level. In addition, short amplicon regions are selected for each target region. 

FAQ-3877
What are the ResDNA Quant Kit components?

The kits are composed of a premixed master mix for CHO and E. coli in liquid format that contains the target. For HEK293 the same composition comes in lyophilized format. The kit also contains an internal control assay detected in Green and Yellow channel, internal control DNA, positive control DNA, and dPCR qualified water. All necessary components are included in the ResDNA Quant Kits.

FAQ-3878
How much sample can I load for detecting host cell contamination?

26k Nanoplates are recommended for resDNA quantification, which maximizes the amount of template that can be loaded within a single reaction. In 26k nanoplates, this corresponds to 28 μl in 40 μl reaction volume. In addition, maximum template loading amounts for each kit will be provided in QSPs. 

FAQ-3879
Is dPCR sensitive to inhibition?

dPCR is less prone to inhibition in comparison to qPCR; however, we recommend dilution of samples that are known to contain PCR inhibitors.

FAQ-3880
How long can I store the reconsituted assay regarding QIAcuity HEK293 resDNA Quant Kit (96) at 4°C?
For optimal performance, the recommendation is to use the reconstituted assay within 72 hours.
FAQ-3934
What is the preferred storage temperature for reconstituted assay for the QIAcuity HEK293 resDNA Quant Kit (96)?
The recommended storage temperature is 4°C for 72 hours.
FAQ-3935
What is the amount of standard for the different kit?
The standard that is provided has an amount of 1000 pg that will be diluted with 100 µL of rehydration buffer down to working solution of 10 pg/µL.
FAQ-3936
How did you calculate the conversion factor?
A serial dilutions of HEK293, CHO, and E. Coli gDNA standard test them using HEK293, CHO, and E. Coli ResDNA Quant Kits, respectively. We then compare the copies per microliter obtained at different loading concentrations. We correlate the number of copies of target amplicon with the loading amount in picogram. To rule out any issues with PCR performance, loss of target amplicons, loading errors, user error, instrument errors, etc. skewing the true conversion factor, we repeat the testing over multiple samples, multiple batches of kits, standards, and multiple users. This gives us our accurate conversion factor.
FAQ-3937
What does the standard kit contain?
The standard for HEK293, CHO, and E. Coli contains genomic DNA, and we recommend digestion of the standard for better migration out into the partitions.
FAQ-3938
What region is targeted in the QIAcuity E. coli resDNA Quant Kit (96)?
The QIAcuity E. coli resDNA Quant Kit (96) is targeting the transcribed genomic regeion of 16S with <200 bp fragment size. 
FAQ-3939
My sample DNA is highly fragmented. What is the principle behind QIAcuity HEK293 resDNA Sizing Kit?
The kit targets a proprietary multicopy human genomic locus to enable sensitive detection and sizing of HEK293 or human residual DNA. By amplifying both a short (83 bp) and a long (345 bp) region at the same locus, it allows accurate assessment of DNA fragmentation. This dual-target strategy supports robust residual DNA quantification for regulatory-compliant quality control.
FAQ-4189
Which dyes/channels are used for the short and long amplicons of QIAcuity HEK293 resDNA Sizing Kit?
The short amplicon (83 bp) is detected in the Green channel. The long amplicon (345 bp) is detected in the Crimson channel. Using two channels enables simultaneous quantification and sizing of residual HEK293 DNA.
FAQ-4191
How can I calculate the median fragment size of residual HEK293 DNA?
QIAcuity HEK293 DNA Sizing Tool is provided on the webpage and can be used for the calculation of the median fragment size. Details are provided in the corresponding handbook (www.qiagen.com/HB-1021).
FAQ-4190
What are the components of QIAcuity Residual DNA Quantification and Sizing Kits? Are controls included?
All the residual DNA kits are composed of a master mix and the respective target assays. The kits also contain an internal control assay, internal control DNA, and positive control DNA. All necessary components for detection of residual DNA are included in QIAcuity Residual DNA Quantification and Sizing Kits.
FAQ-4192
Is dPCR sensitive to inhibition/matrix effects?
Digital PCR is less prone to inhibition in comparison to quantitative PCR. However, we recommend prior dilution or DNA extraction of samples that are known to contain PCR inhibitors like high amounts of protein. Samples can be diluted to match optimal loading amounts for QIAcuity 26k Nanoplates.
FAQ-4193