Cryopreservation of Murine Brain by Snap Freezing: A Technique to Rapidly Freeze Whole Mouse Brain Specimen for Histological Analysis

To cryopreserve murine brain sample by snap freezing, begin by taking a beaker filled with isopentane solution - a highly conductive liquid - and immerse it into a jar containing liquid nitrogen.

Freeze the isopentane till the solution turns viscous.

Meanwhile, take a whole mouse brain sample prefixed in sucrose solution. This treatment prevents brain tissue deformation in the subsequent steps.

Remove the brain sample from the sucrose solution and blot it dry to remove any traces of sucrose.

Next, position the brain in the desired orientation into a deep cryomold containing a layer of embedding medium.

Overlay the brain in the cryomold with more embedding media to ensure the entire organ is covered.

Then, submerge the cryomold containing the embedded brain into the pre-chilled isopentane bath. The rapid cooling of the brain tissue to an ultra-low temperature ensures retention of brain architecture without any distortion.

Now, allow the brain specimen to freeze until the embedding medium solidifies forming a gelatinous layer around the brain, holding it in place.

Once frozen, remove the cryomold from the isopentane bath and wrap the cryopreserved mouse brain in a foil sheet.

Store the sample at minus eighty degrees Celsius for further histological analysis.