FIXATIVE -EM, ADULT ANIMALS

 

2% Paraformaldehyde, 2% Glutaraldehyde, 0.075 M Sodium Cacodylate buffer, pH 7.4

 

Paraformaldehyde
20 g
Glutaraldehyde, 50% solution
40 ml
Sodium Cacodylate
16.05 g
D'H2O
to total volume
 
______________
 
1000.0 ml

Cover and heat Paraformaldehyde on hot plate (2-3 setting) in hood in a 600 ml beaker with 300-400 ml D'H2O. When solution has reached 60-65°C (about 15 minutes) add one or two drops of 10N NaOH to clear. Put in refrigerator or freezer to cool. Add Na Cacodylate powder to 400 mI DD'H2O in a volumetric flask, then add glutaraldehyde. When the paraformaldehyde has cooled (at least to room temperature), filter it and add to the rest of the solution. Bring volume to 1000 ml. Bring pH down to 7.4 witQ 1N HCl.