This is a quick method of getting paraformaldehyde (PFM) into solution. It is a good alternative to the traditional methods which can take hours, and has the advantage that it is so quick that you are more inclined to prepare fresh PFM each time.

CAUTION! Flammable. Irritant vapor. Probably carcinogenic.

Method

0.1 g paraformaldehyde powder in small glass tube
Add 0.5 ml distilled water
Add 1 drop 0.5 - 1.0 M sodium hydroxide

Heat to approx 80 °C for 2-3 mins; shake in water bath until PFM has dissolved. A beaker of very hot water will do.

Add 9.5 ml PBS. Correct pH with HCl if necessary.

Makes 10 ml of 1% PFM solution.