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CRISPR-SNIPER Gene Editing Service

Advanced Gene Editing for Challenging Cases

CRISPR, but better

At REPROCELL, we have collaborated with GenAhead Bio to provide CRISPR-SNIPER Gene Editing Services. This novel
approach to genome modification makes it possible to achieve otherwise challenging mutations. This makes CRISPR-SNIPER the most efficient gene-editing technique on the market. It greatly increases the likelihood of project success — saving you time, effort and money.

SNIPER = Specification of Newly Integrated Position and Exclusion of Random-integration.

DNA model with tweezers picking a nucleotide

The Benefits of SNIPER

  • Increase screening specificity
  • Track iPSC differentiation
  • Solve challenging cases
  • Achieve multiplex gene knock-out and knock-in
  • Save time and money

The modified cells are developed, manufactured or supplied by GenAhead Bio Inc. under license from ERS Genomics Limited.

  CRISPR System CRISPR-SNIPER System
Target cells Mainly cell lines Cell lines and iPSCs
SNP knock-in % < 1% 10-30%
Max. insertion size ~ 2 kbp 5-7 kbp
Conditions tested ~ 1 6-12
Biallelic modifications
KI reproducibility Low High

Six examples of CRISPR-SNIPER in action

1. Insertion of large gene fragments

Normally, the rate of insertion decreases dramatically when your gene of interest (GOI) exceeds 2000 bp. As SNIPER allows optimization of gene editing conditions, it can be used in synergy with CRISPR to knock-in genes up to 7000 bp in size. This is particularly useful for tracking gene expression, as it makes the insertion of functional gene segments less challenging.

For example, you may want to insert fluorescent reporter genes to enable rapid optimization of differentiation protocols or to permit tracking of specific cell populations during differentiation. Alternatively, you may want to knock-in antibacterial resistance genes to assist cell selection.

CRISPR-SNIPER 01 Insertion of large gene fragments

2. Insertion of Biallelic Mutations

Achieving the correct disease phenotype may require the insertion of heterogenous or homogenous mutations. However, with conventional gene editing it is challenging to achieve biallelic gene modifications. Using SNIPER, gene editing conditions can be optimized to allow the creation of heterozygous or homozygous mutants for disease modelling.

CRISPR-SNIPER 02 Insertion of Biallelic Mutations

SNIPER enables editing of both DNA strands to create a homozygous (Ho) and heterozygous (He) genotype in multiple iPSC clones.

3. Increased Screening Efficiency

Thanks to SNIPERʼs enhanced screening efficacy, the system can detect at least 30× more positive clones than conventional screening techniques.

In this way, SNIPER enhances CRISPR-Cas9 gene editing by making it easier to detect cells that contain your desired mutation. This means that CRISPR-Cas9 projects that were once unfeasible can be achieved.

CRISPR-SNIPER 03 Increased Screening Efficiency

CRISPR-SNIPER is at least 30× more efficient than CRISPR-Cas9 alone.

For SNP modification, SNIPER screening detects positive clones at a 30× higher frequency (30%) compared with conventional screening (1%).

4. Knock-out of multiple genes without increasing cell passage number

Editing multiple genes normally involves sequential gene editing experiments, each increasing cell passage number. With the CRISPR- SNIPER system you can edit up to five genes at once, thereby avoiding the effects of extended passaging, such as slow growth, formation of genetic abnormalities, and difficulties in differentiation. A further advantage of this property is the ability to assess the effect of your modification on the interaction of numerous pathway components at once.

CRISPR-SNIPER 04 Knock-out of multiple genes without increasing cell passage number

Multiplex gene KO can be achieved using a range of gRNAʼs with different cleavage capabilities. By optimizing the editing efficacy for each gRNA, a KO model with multiple mutations can be created after just one round of gene editing.

5. Making challenging modifications possible

Thanks to the increased accuracy of SNIPER screening, you can now fulfil gene editing projects that may be impossible using CRISPR-Cas9 alone. This is because SNIPER combines a checkerboard of culture conditions with digital PCR to pre-screen for clones most likely to possess your desired modification. By increasing screening sensitivity, CRISPR-SNIPER makes a wider range of genome modification projects possible – including SNPs, large gene insertions and function gene insertions.

CRISPR-SNIPER 05 Making challenging modifications possible

With SNIPER you can edit up to five genes simultaneously.

6. Achieving more accurate gene editing

It can be difficult to obtain your desired mutation if another sequence shares high homology to your GOI. By optimizing the culture conditions, guide RNA, and adding nickase to each gene editing experiment our scientists can increase the specificity of CRIPSR gene editing even further – ensuring that we only provide the cells you want.

The graph below illustrates that our optimized gRNA results in selective knock-down of HLA-A, whilst the HLA-B gene remains undisturbed. This is a large improvement over the results attained with non-specific RNA used in conventional gene editing, which results in knock-down of both alleles rather than one.

CRISPR-SNIPER 06 Achieving more accurate gene editing

Compared with conventional gene editing techniques, SNIPER can isolate similar mutants at a high success rate.

Your Custom Gene Editing Project

Editing multiple genes normally involves sequential gene editing experiments, each increasing cell passage number. With the CRISPR- SNIPER system you can edit up to five genes at once, thereby avoiding the effects of extended passaging, such as slow growth, formation of genetic abnormalities, and difficulties in differentiation. A further advantage of this property is the ability to assess the effect of your modification on the interaction of numerous pathway components at once.

Project stages:

  1. Bulk screening for optimal conditions
  2. Scheduled cloning
  3. Cell expansion and QC

CRISPR-SNIPER Stage-1 Bulk screening for optimal conditions

Action Points

  • Optimize gRNAs
  • Set Optimal Conditions
  • Perform Transfection
  • Complete First Screening

Check Points

  • Confirm transfection condition by bulk screening with PCR

CRISPR-SNIPER Stage-2 Scheduled cloning

Action Points

  • Select Positive Clones
  • Pick-up Positive Clones
  • Perform Second screening

Check Points

  • Verification of Gene Editing Success via PCR

CRISPR-SNIPER Stage-3 Cell expansion and QC

Action Points

  • Expansion of Positive Clones
  • Quality Checks
  • Cryopreservation of Cells
  • Delivery of Cryovials

Check Points

  • Verification of DNA sequence
  • Screening Undifferentiated Marker Expression
  • Mycoplasma Testing

Make an Inquiry

At REPROCELL, our scientists understand that your custom gene editing project must be as unique as your research. If you have any questions about our CRISPR-SNIPER service, please make an inquiry using the form below.