Mar 20, 2024

Public workspacePreparation of Free Floating Coronal Mouse Brain Sections

  • 1Van Andel Institute
Open access
Protocol Citationmadalynn.erb Erb 2024. Preparation of Free Floating Coronal Mouse Brain Sections. protocols.io https://dx.doi.org/10.17504/protocols.io.dm6gp3pb8vzp/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: February 09, 2024
Last Modified: May 31, 2024
Protocol Integer ID: 95137
Keywords: ASAPCRN
Disclaimer
The protocols.io team notes that research involving animals and humans must be conducted according to internationally-accepted standards and should always have prior approval from an Institutional Ethics Committee or Board.
Abstract
This protocol details the preparation of free floating coronal mouse brain sections.
Attachments
Materials
Materials:

Cryoprotectant solution
AB
Phosphate buffer0.1 M
Sucrose30%
Ethylene Glycol30%

Collect Mouse Brain Tissue
Collect Mouse Brain Tissue
2d
Deeply anesthetize mice via intraperitoneal injection of 2X Avertin solution.
Perform transcardial perfusion using chilled saline solution
Keep 0.9% NaCl TemperatureOn ice .
Use approximately Amount60 mL saline solution per mouse.
Pipetting
Switch from saline solution to chilled PFA.
4% paraformaldehyde in Concentration0.1 Molarity (M) phosphate buffer (PB) Ph7.4 .
Use approximately Amount60 mL PFA per mouse.
Pipetting
Remove brain immediately after PFA perfusion.
Incubate brain in PFA for Duration24:00:00 at Temperature4 °C .
1d
Incubation
Transfer brains to 30% Sucrose / Concentration0.1 Molarity (M) Phosphate Buffer (PB) – keep at Temperature4 °C for ≥ Duration24:00:00 .
1d
Tissue should be completely saturated with sucrose before sectioning.
Brains will sink to the bottom of the vial when saturated.
Section Tissue
Section Tissue
Use a Leica SM2010R Microtome.
Blade: Leica 16cm, knife angle set at 0 degree.
Cut thickness: Thikness35 µm .
Adjust the microtome platform so that it is level with the blade and lock it into place.
Chill the microtome platform by covering it with crushed dry ice.
Apply 5-10 drops of 30% Sucrose / Concentration0.1 Molarity (M) Phosphate Buffer (PB) solution to the chilled microtome platform and wait for it to solidify.
Pipetting
Use the microtome to gently shave the solidified sucrose to make a flat surface.
Use a razor blade to remove any spinal cord from the brain making a flat surface perpendicular to the rostral / caudal axis.
Apply 2-3 drops of sucrose to the existing sucrose platform and quickly position the brain with the olfactory bulbs pointing upwards.
Pipetting
Apply 2-3 more drops of sucrose to the top of the brain to securely freeze it to the microtome platform.
Pipetting
Gently cover the brain in crushed dry ice to freeze the tissue.
Adjust the microtome platform so that the rostral / caudal axis is perpendicular to the blade and the dorsal / ventral axis is level with the blade.
Collect sections in a 24-well plate prefilled with cryoprotectant solution (Concentration0.1 Molarity (M) PB +30% Sucrose + 30% Ethylene Glycol).

Cryoprotectant solution
AB
Phosphate Buffer0.1 M
Sucrose30%
Ethylene Glycol30%

Seal plate with parafilm and store tissue at Temperature-20 °C .