1. Dissect embryo in PBS and add KCL if heart desired in diastole.
2. Make fix w/ dye mix using following recipe: 10 mL 10% Formalin Fix, 1 mL of Indian Ink dye.
3. Place embryo in dye mix for 12-24 hours.
4. Acquire M1 Embedding Matrix embedding media and add Indian Ink drop wise while stirring until M1 media appears black uniformly.
5. Place small amount of embedding media mix forming thin layer on the bottom of the cyromold.
6. Place embryo in embedding media and position in orientation desired.
7. Add embedding media mix until the embryo is completely covered.
8. Place mold on dry ice until embedding media is frozen.

Embedding Media: ThermoShandon - M1 Embedding Matrix

Indian Ink: Higgins Calligraphy Black Ink