Transgenic Service

Frank van der Hoeven / Ulrich Kloz

Microinjection

Microinjection: Under a microscope, a fine needle (right) is inserted into a mouse embryonic cell held by a suction pipette.
© dkfz.de

The Transgenic Service supports scientists at the DKFZ in the generation of genetically modified (transgenic) mouse lines. This procedure involves inserting or deleting DNA sequences into the animals’ genetic material. Depending on the scientific question an inserted gene can be translated into a biologically active protein, or a specific gene of the recipient animal can be modified or silenced.

Three main methods are used for generating genetically modified mice (e.g., as model systems for investigating human diseases):

DNA microinjection: Foreign DNA is injected into fertilized mouse egg cells (zygotes) which are borne by foster mice. Part of the newborn mice will have integrated the foreign DNA into their own chromosomes.

CRISPR/Cas (endonuclease mediated genome editing): RNA (gRNA and Cas9 mRNA) and DNA (template) are injected into fertilized mouse egg cells (zygotes) which are born by foster mice. Part of the newborn mice will have integrated a specific genetic modification into the mouse genome.

ES cell microinjection: DNA is introduced into embryonic stem cells (ES cells) of mice and these are then injected into early mouse embryos (blastocysts). The cells containing the foreign DNA will be integrated into the embryo. Thus it is possible to generate mice with mutations in specific genes (such as “knockout” mice). The effects observed in mice with such knockout mutations provide insight on the biological function normally performed by the silenced gene.

to top