Microinjection for CRISPR: Key Parameters in the Generation of Animal Models

Transgenic animals have become an essential tool in biomedical research, making a decisive contribution to our understanding of diseases and basic cellular processes. Today, pronuclear or cytoplasmic microinjection remains one of the most widely used methods for genome editing and the production of animal models.In this context, the micromanipulation system and the inverted microscope are not merely accessories but critical elements that determine injection precision, sample integrity, and the reproducibility of results.

Key Parameters in CRISPR Microinjection

In the daily routine of a laboratory working with CRISPR in animal models, several technical factors condition the success of microinjection:

High-precision movement control

Working with zygotes and pronuclei requires extremely fine movements along all three axes. The system must allow a progressive and controlled approach of the capillary, with immediate response to the control interface and no intermediate “jumps.” This reduces corrective manoeuvres and helps maintain cleaner, more reproducible entry in each injection.

Mechanical stability and vibration reduction

Any vibration or mechanical play translates into unwanted movements of the capillary over the sample. A system with high mechanical stability and virtually vibration-free operation helps maintain capillary position during contact with the zygote or pronucleus—especially relevant when working with sensitive early embryos and high-throughput workflows.

Positioning management and operator ergonomics

Beyond momentary precision, routine work requires:
• return-to-position (Home) functions,
• position memory,
• and travel limits—especially on the Z axis—to prevent capillary breakage or excessive contact with the sample.
Combined with an ergonomic controller design, this allows longer sessions with less fatigue while maintaining consistent movement quality.

Integration with microinjection systems

The micromanipulator does not work in isolation: it must coordinate with electronic microinjectors and, in some cases, piezoelectric systems. The ability to connect directly to microinjectors such as FemtoJet® 4i/4x or systems like PiezoXpert® simplifies setup, reduces unnecessary cabling, and helps standardise protocols across users.

Adaptation to demanding genetic-editing applications

Injecting a simple marker is not the same as pronuclear or cytoplasmic injection in CRISPR/Cas or TALEN projects. A system designed for these applications must allow users to:

1. work with oocytes and early embryos,
2. handle different sample types (suspended cells, microparticles, etc.),
3. and offer user profiles tailored to the technique (cell transfer, DNA/RNP injection, etc.).

TransferMan® 4r in Microinjection Applications for CRISPR

Microinjection of CRISPR components into zygotes and embryos requires extreme precision, mechanical stability, and a smooth workflow. The TransferMan® 4r electronic micromanipulator meets these needs in genetic-engineering, transgenesis, and animal-model production environments:

• It incorporates the DualSpeed™ joystick, designed for precise, intuitive, and dynamic movement control across all three axes, with very direct transmission of displacement and an almost “real-time” response feel.
• It provides very high mechanical stability, enabling virtually vibration-free operation—crucial for maintaining capillary position during the microinjection of zygotes and embryos.
• It includes smart operator-support functions, such as enhanced automated Home, position memory, and a programmable Z-axis limit to prevent capillary breakage, all contributing to safer and more efficient positioning management.
• It is ready to integrate into a complete microinjection ecosystem thanks to its connection with PiezoXpert®, FemtoJet® 4i/4x microinjectors, and various adapters for major inverted microscopes. This enables the setup of work systems for micromanipulation of oocytes and early embryos, pronuclear and cytoplasmic injection, and gene-editing applications using CRISPR/Cas.

Thus, TransferMan® 4r is not presented as a standalone device but as a solution that translates into practice the technical criteria that make the difference in CRISPR microinjection.

Conclusions

For laboratories working intensively with CRISPR in animal models, the right combination of micromanipulation system, microinjectors, and inverted microscope is key to ensuring precision, reproducibility, and safety in every microinjection.
If you are considering reviewing or optimising your CRISPR microinjection setup, our team can help analyse your current workflow and evaluate which micromanipulation and injection options best fit your experimental needs.