1. Dissect embryo in PBS.
2. Place in 10% Formalin Fix for 12 hours.
3. Dehydrate embryo with the same processing times indicated for paraffin processing except xylene washes are not needed.
4. Melt PEG at 42ºF in oven.
5. Add analine dye (Sudan IV) to melted PEG (usually 10% by volume).
6. Infilitrate with PEG w/ dye mix for 12 hours in 42ºF oven.
7. Place PEG in plastic mold.
8. Place embryo in embedding media and position in orientation desired.
9. Add embedding media mix until the embryo is completely covered.
10. Place on ice until PEG has become solid.

Embedding Media: Sigma-Aldrich - Polyethyline Glycol

Dye: Sigma-Aldrich - Sudan I