Stereotactic Microinjection of a Viral Vector for Gene Manipulation in a Mouse Pup Striatum

Take a genetically modified mouse pup carrying a loxP-flanked STOP cassette that blocks red fluorescent protein or RFP expression.

Secure the pup on a custom-made stereotaxic frame and cover it with ice to maintain anesthesia.

Disinfect the scalp and mark lambda as the reference point.

Align the injection needle to striatal coordinates relative to lambda and puncture the skull.

Retract the needle to the skull surface, then insert it into the target depth.

Inject the dye-mixed viral vector into the striatum at a controlled rate. The vector encodes green fluorescent proteins or GFPs and Cre recombinase.

Withdraw the needle slowly to prevent solution backflow.

Remove the pup and allow recovery.

In striatal cells, the virus releases its genome, enabling the expression of Cre recombinase and GFP. Cre excises the loxP-flanked STOP cassette, activating RFP expression.

Simultaneous GFP and RFP expression confirms successful gene manipulation.

Position the pup with the glove in the head tray and put some crushed ice around the latex sleeve to maintain the hypothermia anesthesia. Then scrub the pup's head with 70% ethanol and locate the lambda landmark. Mark it with a marker. Then aim the needle tip