Reagent	Final concentration	Amount
25% glutaraldehyde (GA)	2.5%	1.00 mL
20% paraformaldehyde (PFA)	2%	1.25 mL
0.2 M cacodylate buffer, pH 7.4	0.1 M	5 mL
dH2O	N/A	2.75 mL
Total	N/A	10 mL

Fixative should always be prepared freshly on the day of the experiment.