For 500 ml 2% Paraformaldehyde Solution
- Allow paraformaldehyde (PFA) powder (Aldrich #30525-89-4 or Sigma P-6148) to come to room temperature (Stored in refrigerator)
- Weigh 10.0 g PFA in fume hood
- Flush container with Argon or Nitrogen to prevent air decomposition of p-formaldehyde.
- Dissolve in 475 ml distilled H2O in 60-70º C water bath on hot plate in fume hood. Do not allow water bath to go over 70ºC (formaldehyde will vaporize!).
- While disolving, label 100 X 4 ml and 7 X 12 ml tubes (or other combinations of useful aliquots) with 2% PFA and the date
- After @ 1 hr add 1 or 2 drops of 5M NaOH. Cloudy suspension will then turn clear.
- Allow to cool to room temperature (@ 2 hours).
- Add 25 ml 20X PBS (see recipe) and adjust pH to 7.3.
- Filter, aliquot into tubes and freeze. Aliquots good for at least 5 years.
Thawed aliquots are stable at 4º C for up to 2 weeks.
Dilute 1 part 2% PFA to 3 parts cells in PBS (eg 60 µl + 180 µl to yield 0.5% final concentration).
- Becton Dickinson Immunocytometry Systems Source Book (1989) 2.10
- Lanier, L.L., and Warner, N.L. (1981) Paraformaldehyde Fixation of Hematopoietic Cells for Quantitative Flow Cytometry (FACS) Analysis. Journal of Immunological Methods 47, 25