--- title: LockSeq Service | Off-Target Confirmation, DNA-In to Report-Out | Countagen description: Send us your DNA and off-target coordinates. We return a UMI-corrected variant allele frequency report in 15 business days. No capital expenditure. No infrastructure. End-to-end service. image: https://www.countagen.com/hubfs/og-home-2026-10.png --- [![Logo\_horizontal\_colored logo with black text](https://www.countagen.com/hubfs/Logo_horizontal_colored%20logo%20with%20black%20text.png)](https://www.countagen.com/?hsLang=en) - [Technology](https://www.countagen.com/technology?hsLang=en) - [Bioinformatics](https://www.countagen.com/bioinformatics?hsLang=en) - [Sample Report](https://www.countagen.com/lockseq-sample-report?hsLang=en) - [Resources](https://www.countagen.com/resources?hsLang=en) - [FAQ](https://www.countagen.com/faq?hsLang=en) - [About Us](https://www.countagen.com/about-us?hsLang=en) [Request a quote](https://www.countagen.com/contact?hsLang=en) Off-target confirmation service # Confirm your on- and off‑target edits, from coordinates to report. You define the targets. We design the panel, run LockSeq in our lab in Solna, Stockholm and deliver an analyzed report in 15 business days. No instrument investment, no bioinformatics overhead. [Request a quote](https://www.countagen.com/contact?hsLang=en)[See a sample report](https://www.countagen.com/lockseq-sample-report?hsLang=en) [▶  Watch how LockSeq works (2 min)](https://www.countagen.com/technology?hsLang=en#explainer) LockSeq report · results Illustrative data 290 / 300 sites reportable 1 off-target edit found | Site | Edited | Control | Call | | --- | --- | --- | --- | | **DP-001** on-target | 71.3% | 0.00% | Edited | | **DP-187** off-target | 0.23% | 0.00% | Edited | | **DP-069** off-target | 0.52% | 0.58% | In control | | **DP-004** off-target | 0.00% | 0.00% | No variant | Mean variant frequency, 3 replicates[View full sample report →](https://www.countagen.com/lockseq-sample-report?hsLang=en) Trusted by teams at ![Integra Therapeutics](https://www.countagen.com/hs-fs/hubfs/Integra_Therapeutics_logo_black.png?width=400&height=198&name=Integra_Therapeutics_logo_black.png) ![Danish Cancer Institute](https://www.countagen.com/hs-fs/hubfs/Danish%20Cancer%20Institute.png?width=634&height=346&name=Danish%20Cancer%20Institute.png) ![Karolinska CRISPR Functional Genomics Unit](https://www.countagen.com/hs-fs/hubfs/Karolinska_CRISPR_Functional_Genomics_Unit_black.png?width=944&height=472&name=Karolinska_CRISPR_Functional_Genomics_Unit_black.png) ![University Freiburg](https://www.countagen.com/hs-fs/hubfs/University%20Freiburg.png?width=766&height=102&name=University%20Freiburg.png) ![NIST Gene Editing Consortium](https://www.countagen.com/hs-fs/hubfs/NIST%20Gene%20Editing%20Consortium.png?width=950&height=226&name=NIST%20Gene%20Editing%20Consortium.png) > LockSeq has been instrumental in scaling our validation panels for off‑target candidates, a key process in the safety assessment of our gene writing platform. The Countagen team's approachable expertise and dedicated support with data interpretation have added value to our research. > > **Marta Sanvicente García, PhD** > Bioinformatics Scientist, Integra Therapeutics The regulatory context ## FDA draft guidance puts off‑target confirmation before the IND The FDA's April 2026 draft guidance on genome editing safety asks for confirmatory testing at nominated off‑target sites, names probe‑based sequence enrichment among the methods, and expects these studies done before the original IND. As panels grow, keeping sensitivity and complete target coverage gets harder. Missing sites are data blind spots that can turn into delays and regulatory risk. That confirmation step is what LockSeq does. 1 Nominate Candidate sites from your nomination assay or in silico prediction. 2 Confirm with LockSeq An independent, targeted readout of every nominated site in your edited samples. 3 Report Edit frequencies per site, ready for your safety package. How it works ## What's included in every LockSeq study An end-to-end service: you focus on your program, we deliver high-confidence edit detection. 01 · Scoping ### Project scoping We review your edit design, gRNAs and nominated off‑target coordinates, and add in silico nomination where needed. Usually within 24 hours. 02 · Panel ### Panel design Padlock probes for all your on‑ and off‑target loci, designed for 1,000+ sites per reaction. Add new targets later without redesigning the panel. 03 · Lab ### Sequencing Library prep and sequencing in our lab in Solna, Stockholm, on Illumina, MGI or Oxford Nanopore. 04 · Report ### Consensus report UMI-corrected VAF per site with indel profiling, coverage charts and raw data (FASTQ + BAM). 15 business days from DNA receipt. ![High-Level Workflow](https://www.countagen.com/hs-fs/hubfs/High-Level%20Workflow%20(3).png?width=2000&height=448&name=High-Level%20Workflow%20(3).png "High-Level Workflow") 0.1% VAF detection limit as standard, lower with deeper sequencing 1,000+ sites per reaction, by design 15 days business days, DNA receipt to report 3 platforms: Illumina, MGI & ONT Why LockSeq ## Built so a sequencing error never reads as an off‑target ### High-confidence edit detection Every captured molecule gets a UMI before amplification, and reads are collapsed into one consensus call per molecule. Confident calls at 0.1% VAF as standard, and below that with deeper sequencing. Every site’s own limit is shown in the report. ### Every site clearly reported Sites we can't design for are flagged before you send samples. Every other site gets a clear status in the report, including any that drop out in the lab. ### Small and large panels, same workflow From a single site to large off‑target panels. Add targets without redesigning the assay. Pricing ## Projects start from €1,000 For example, a panel of up to 25 sites with 2 samples. Price scales with sites and samples. Most projects are scoped within 24 hours. **Every quote includes:** panel design · library prep & sequencing · UMI-corrected VAF per site · indel profiling · coverage charts · raw data (FASTQ + BAM) [Request a quote](https://www.countagen.com/contact?hsLang=en)[See a sample report](https://www.countagen.com/lockseq-sample-report?hsLang=en) [Request a quote](https://www.countagen.com/contact?hsLang=en) Partners [![ClearCut Biolabs](https://www.countagen.com/hubfs/ClearCut_logo_provided.png)](https://clearcutbiolabs.com) Genome editing kits and reagents. [![Corn Lab, ETH Zurich](https://www.countagen.com/hubfs/CornLab_logo.png)](https://cornlab.com) Off-target nomination with AutoDISCO. [![Edilytics](https://www.countagen.com/hubfs/Edilytics_logo_dark.svg)](https://edilytics.com) Building LockSeq Mode for CRISPResso. 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