Isolating Immune Cells from Mouse Choroid Plexuses

Position a mouse's brain dorsal side up.

Under a microscope, separate the cerebral hemispheres. Pull away the cortex and then the hippocampus to expose the lateral ventricles and the third ventricle.

Collect two lateral choroid plexuses. These are immune-cell-rich brain structures that line the lateral ventricles like a long veil.

Collect the third ventricle choroid plexus, which is a short structure with a granular surface.

Detach the cerebellum to expose the fourth ventricle.

Collect the fourth ventricle choroid plexus, which is a long globular structure with a granular surface.

Place all the choroid plexuses in a tube with buffered saline to maintain tissue integrity.

Add a digestive enzyme solution and incubate with agitation.

The enzyme breaks down the extracellular matrix and loosens the cells.

Add a suitable buffer to inactivate the enzyme.

Centrifuge to settle the cells. Discard the supernatant and resuspend the cells in a fresh buffer for further analysis.