4% PARAFORMALDEHYDE

 

 

4% PARAFORMALDEHYDE
4% paraformaldehyde solution(generally, make before 1 day fixing)
(0.1M PB buffer : 40g paraformaldehyde powder)
40g paraformaldehyde powder
250ml 0.1M phosphate buffer(pH 7.4)
750ml distilled water
10N sodium hydroxide

1. Heat the DW until 60 degree
2. Turn off heat and slowly add the paraformaldehyde powder
3. Stir until powder is dissolved, then add NaOH dropwise(about 5-10 drops) until solution is clear.
4. Cool to room temp
5. Filter through Whatman #4 or 5(and check pH 7.2-7.4)
6. Keep cold in ice or refrigerator before use.