Frequently Asked Questions

The exact amount depends on the specific product and lot. This information is provided in the Certificate of Analysis (CoA), available in the Documents section of the product page.

Product concentration is documented in the CoA, which can be downloaded from the Documents section of the corresponding product page.

Fragment size information depends on the specific product and lot. These details are included in the CoA, available in the “Documents” section of the product page.

Allele frequency is determined for each product lot using dPCR and documented in the CoA. If you require an allele frequency not available in our retail product range, SensID can manufacture custom lots tailored to your specifications. For specific cfDNA reference sets, we also provide matching wildtype cfDNA for dilution as part of the specific set, enabling you to achieve the exact allele frequency your assay requires.

All of these parameters are product- and lot-specific. Exact values are documented in the CoA, which can be downloaded from the “Documents” section of the product page on our website.

As part of quality control, SensID evaluates DNA concentration using the Qubit 4 Fluorometer with the dsDNA HS Kit, fragment length using Agilent D5000 ScreenTape, and allele frequency or fusion copy number by SI-traceable digital PCR using the QIAGEN QIAcuity Four. The specific methods and results for each product are documented in the CoA provided with each batch.

Based on the purification processes used during manufacturing, our cfDNA in buffer and gDNA in buffer products are not expected to contain proteins. However, testing for protein content is currently not part of the product specification and is therefore not routinely performed. To date, we have not received any customer feedback indicating the presence of proteins in these materials.

Retail products are typically available immediately and can be shipped within one to a few business days. Lead times for custom products depend on project complexity and usually range from 8–12 weeks.

For retail products, you can request a quotation directly by clicking the “Request Product” button on the product page. For custom products, please contact our technical team at info@sens-id.com. We will be happy to discuss your requirements and prepare a tailored quotation.

SensID routinely develops custom reference materials to meet specific customer needs. Simply contact us with your specifications, such as material type, matrix, or allele frequency, and our scientific team will evaluate feasibility and provide a tailored solution.

For details, please reach out to our technical team at info@sens-id.com.

All product-related documents can be downloaded from the product page on our website. Typically, you will find:

• Certificate of Analysis (CoA): Lot-specific quality control results, including methods, concentration, amount, and allele frequency.
• Instructions for Use (IFU): Practical guidance for handling, usage, and dilution preparation.
• Safety Data Sheet (SDS): SensID products do NOT require an SDS from a regulatory perspective, because the substances used are considered non-hazardous in the amounts/concentrations used. Therefore, we provide SDS on a courtesy basis only.

Flyers for SensID products are available on the Oncology Controls landing page.

Yes. SensID provides matching wildtype cfDNA that can be used to dilute down to your desired allele frequency. Each reference set includes the matching wildtype cfDNA, and we recommend using only this material for dilution. A Pearson Square mixing method is suggested for this purpose, with step-by-step instructions provided in the IFU

Alternatively, SensID can also manufacture a custom lot directly at your specified allele frequency. For details, please contact our technical team at info@sens-id.com.

SensID provides matching wildtype cfDNA that can be used to dilute down to your desired allele frequency. Each reference set includes its corresponding wildtype, and we recommend using only this material for dilution.
To calculate the correct proportions, the Pearson Square method can be applied. This graphical approach determines how much mutant and wildtype cfDNA should be mixed to reach the target allele frequency.

How it works (example with ESR1 0.94% AF diluted to 0.1% AF):

1. Draw a square and place the starting concentration of one solution (e.g., 0.94% AF of ESR1 mutant top left corner, and the other solution (e.g., 0.01% WT of ESR1) on the bottom left corner.
2. Write the desired target concentration (e.g., 0.1% AF) in the center of the square.
3. Subtract diagonally to calculate the balancing values. Take the positive values only.
• Subtract the wildtype from the target concentration resulting in A (e.g., A= 0.1% – 0.01% AF = 0.09%).
• Subtract the initial concentration from the target concentration resulting in B (e.g., B= 0.1% – 0.94% AF = 0.84 – disregard the negative).
4. Divide each of the generated values (A and B) by their sum to determine the mixing ratio. In the given example: 9.67% of 1% AF ESR1 mutant and 90.33% wildtype should be mixed to generate 0.1% AF solution.

Important notes:
• Dilutions are only possible for mixing vials (wildtype with mutant) from a single reference set, because only this way it is guaranteed that the wildtype is from the same lot/background.
• Cross-reactivity may vary depending on assay conditions (e.g., PCR temperature) used.
• Users must check and correct for potential cross-reactivities if combining vials.

Yes. SensID offers Plasma (human-tech) + cfDNA/ctDNA products that serve as allele frequency standards for liquid biopsy workflow controls. At present, only one retail product is available: SID-000152 cfDNA in Plasma for Metagenomics.
For custom projects, we routinely manufacture plasma-based workflow controls tailored to your requirements. The typical minimum order quantity for such custom productions is around 90 vials. For more information, please contact our technical team at info@sens-id.com.

SensID makes it simple to prepare cfDNA in plasma by combining one of our DNA-free plasma products with one of our cfDNA/ctDNA products. cfDNA can then be spiked into plasma using a straightforward mixing protocol.
Because cfDNA concentrations in patient samples vary, reference values from international proficiency testing programs may be used (typically ~30 ng/ml, though some providers use up to 80 ng/ml). Detailed step-by-step instructions, including calculation examples, are available in the IFU.
For customers preferring ready-to-use solutions, SensID also manufactures plasma-based workflow controls as custom projects, typically with a minimum order quantity of 90 vials. Please contact our technical team at info@sensid.com for details.

The Protocol to prepare a homogenous suspension:

1. Preparation: Briefly centrifuge the cfDNA and plasma to avoid liquid remaining in the vial caps. Work in a clean environment (e.g., a laminar flow hood) to prevent contamination.
2. Submitting 1X Plasma: Pipette a defined volume of 1X plasma appropriate for your workflow requirements.
3. Adding cfDNA: Add an appropriate amount of cfDNA (Refer to CoA for the cfDNA concentration).
4. Mixing: Mix the suspension by gently pipetting up and down

Please note:

• Because cfDNA concentrations in patient samples can vary, reference values from international proficiency testing programs may be used (typically ~30 ng cfDNA per ml of plasma are used, though some providers use up to 80 ng/ml).
• The actual amount available after extraction depends on the extraction efficiency of the system used.
• Adjust the volumes as needed depending on your cfDNA target concentration.
• Regularly validate the results, especially when changing the extraction system or the source of cfDNA.

Example:

For customers who prefer ready-to-use solutions, SensID also manufactures plasma-based workflow controls as
custom projects, with a typical minimum order quantity of around 90 vials. For further details, please contact our
technical team at info@sens-id.com.

The DPYD 100% mutant material is produced by spiking a very high proportion of mutant molecules into a wildtype background, which means a small fraction of wildtype DNA is always present. As a result, highly sensitive methods such as dPCR or NGS usually measure slightly below 100% mutant. In this context, 100% mutant is a nominal designation with an acceptance range of 95–105%. The exact measured value for each lot is documented in the Certificate of Analysis (CoA).

SensID’s DNA-free plasma contains human serum proteins at common plasma concentrations, electrolytes, and EDTA. Residual DNA is assessed for each lot as part of quality control using Real-Time PCR. Together, these characteristics support its use in method development and performance evaluation in molecular assay workflows.

The novel truly patient like n-ctDNA by SensID combines several characteristics:

• A Fragmentation pattern reflecting the natural nucleosome-bound distribution of cfDNA, ensuring high commutability to real patient samples.
• A superior low mutational background, enabling highly sensitive NGS assays including MRD testing (Important for the Limit of Blank/Detection/Quantification of an assay).
• A proven performance across platforms including NGS and dPCR, with High library conversion rates.

Further details are available here

SensID reference materials have been shown to be compatible with diverse analytical platforms, including workflows using NGS, qPCR, and dPCR. Their broad applicability makes them a practical option for molecular workflows, including liquid biopsy assay development, optimization, and performance evaluation.

Optimizing an assay is especially important during the establishment phase to ensure that all variants of interest are reliably detected. While a single reference product can provide useful information, we generally recommend working with cfDNA reference sets that include variants at different allele frequencies and taking a temperature-optimized approach to assay setup. A more robust strategy is to use a comprehensive validation kit (e.g. EGFR set with 0%, 0.1%, 1%, and 5% allele frequencies) or to combine multiple products across runs and batches. This ensures greater confidence in both the sensitivity and reproducibility of your workflow.

Failure to detect certain variants in dPCR can arise from a combination of technical and sample-related factors. The most common factors include:

• Assay Sensitivity and Specificity: The dPCR assay may lack the sensitivity to detect very low-frequency variants. If variants are present below the assay’s detection limit, they may be missed altogether.
• PCR Inhibition: Inhibitors in the sample like proteins, salts, or other contaminants can interfere with the PCR reaction, leading to low VAFs or missed variants.
• Suboptimal Assay Conditions: Precise dPCR conditions (e.g., annealing temperatures, cycling parameters, reagent concentrations) are crucial for accurate detection. Inconsistent conditions can skew results.
• Primer/Probe Efficiency: Subpar primer/probe binding may occur due to degradation or specificity issues. Checking primer quality and confirming specificity can help resolve detection problems.
• Mutant Allele Dropout: Certain mutations may undergo dropout during PCR due to secondary structures or sequence-specific challenges, leading to reduced detection rates for those variants.
• Target Coverage: Insufficient or uneven coverage of target regions may miss mutations if certain gene regions aren’t fully covered by the assay design.
• Laboratory Technique Variability: Differences in pipetting, handling, and other manual steps can introduce variability, affecting detection. Consistent technique is essential for reliable results.
• Instrument Calibration: Small calibration discrepancies in dPCR machines can alter sensitivity thresholds, impacting detection accuracy.

Each of these factors alone may have a minor impact, but in combination, they can significantly influence the likelihood of successful variant detection.