How do you get pH from PFA?

Adjust the pH to 7.4 with 1 M HCl (~1 mL), then adjust the final volume to 100 mL with H2O. Filter the solution through a 0.45-μm membrane filter to remove any particulate matter. Make the paraformaldehyde solution fresh prior to use, or store in aliquots at −20°C for several months. Avoid repeated freeze/thawing.

How do you dilute a PFA?

Dilute 1 part 2% PFA to 3 parts cells in PBS (eg 60 µl + 180 µl to yield 0.5% final concentration).

How do you make a 4% PFA solution?

Procedure

  1. For 1 L of 4% Formaldehyde, add 800 mL of 1X PBS to a glass beaker on a stir plate in a ventilated hood.
  2. Add 40 g of paraformaldehyde powder to the heated PBS solution.
  3. The powder will not immediately dissolve into solution.
  4. Once the paraformaldehyde is dissolved, the solution should be cooled and filtered.

Does PFA dissolve in water?

Paraformaldehyde is a high polymer, and its molecules are too big to dissolve in water, alcohol or anything else. You have to depolymerize paraformaldehyde to get it to “dissolve” and form a formaldehyde (really methylene hydrate) solution.

How do I make a 20% PFA?

Formaldehyde stock solution (20%) Add 200 mg of EM-grade paraformaldehyde per milliliter of H2O. Heat at 60°C on a stir plate in a ventilated chemical fume hood to dissolve. Add a trace of NaOH to help dissolve the paraformaldehyde (no more than 1 mL of 1 N NaOH to 100 mL of H2O).

Can you warm PFA?

Heating of the paraformaldehyde is not necessary, since depolymerization may take place at room temperature. We conclude that formaldehyde prepared from paraformaldehyde remains stable for considerable periods of time, and it is therefore unnecessary to prepare it immediately prior to fixation.

How long can I store 4% PFA?

Unopened bottles can be stored at room temperature for at least 5 years. After opening, the solution can be stored in the original bottle for at least a month at 4°C, protected from light.

Can you store PFA in plastic?

If you want to be sure to have maximum reactivity, only use freshly thawed solutions and discard the rest. Using glass or plastic bottles does not make any difference at all.

How do you get 10% PFA?

recipe for 10% PFA: add 25g PFA to 250ml water . Heat at 50 degrees till dissolve. diluting 10% PFA to 4% PFA: 10ml of 10% PFA + 2.5ml 10X PBS + 12.5ul of 20% triton + 12.375ml H2O.