Specimen Preservation Procedure

Written by Russell McAndrews

1. Fix specimen by submerging in a 10% buffered formalin* solution for 48  hours.
2. Transfer to distilled water for 24 hours.
3. Dehydrate specimen through an ethanol series, (10%, 30%, 60%, 70%) for a  period of 24 hours in each solution.
4. Store in a 70% ethanol.

Suggested recipe for buffered formalin:

• formaldehyde solution 100mL
• Sodium acid phosphate (NaH₂PO₄-H₂O) 4.0g
• Anhydrous disodium phosphate (Na₂HPO₄) 6.5g

Check pH, adjust to 7.0 with NaOH or H₃PO₄ if necessary.  Dilute to final volume of 1.0 L.

NOTE: Formalin is combustible, an irritant and may cause cancer. Use glove and adequate ventilation. Store in flame proof cabinet.