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Aoyama’s Fluid

Aoyama’s Fluid


Cadmium chloride10g
Strong formalin150mL
Distilled water850mL


The formula specifies that the strong formalin should be neutralized. Using a freshly purchased solution may avoid this, but if it does not, neutralize by layering the strong formalin over calcium carbonate (marble chips or crushed oyster shells) overnight in a loosely covered container under a fume hood.

Never do this in a closed container. Enough carbon dioxide can be generated for the pressure to break a glass jar.

This fixative is useful for the Golgi apparatus and general morphology. Average-sized pieces should be fixed within 4 to 12 hours. There is no special after-treatment.

Safety Note

Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.


  1. McManus, J.F.A. and Mowry, R.W., (1960),
    Staining methods, histologic and histochemical,
    Harper & Row, New York, NY, USA.