Fixation with paraformaldehyde

Contributed by Martin Fitzpatrick, University of Birmingham, United Kingdom

Fixation with paraformaldehyde

  • Add 41.5ml 2.26% sodium dihydrogen orthophosphate to a suitable heat-proof container
  • Add 8.5ml sodium hydroxide 2.52%
  • Heat to 60-80’C in a covered container
  • Add 2g ‘Analar’ paraformaldehyde, stirring thoroughly until dissolved.

Adding a couple of drops of 1M NaOH can help the PFA dissolve.

  • Allow to cool and filter to remove particulates. Recheck pH.
  • Store at RT and ideally use within 48h.

This method is based, with permission, on an original protocol available here.