paraformaldehyde solution - for IHC (Mar/12/2008 )

hallo,

stupid question, but I know that i should not mess with paraformaldehyde. how do i prepare 4% paraformaldehyde for immunohistochemistry? are there any tips and tricks? storage time and temperature could also be important.



thanks for suggestions

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4g of PFA in 60 mL water
heat 60-70 °C
add few drops of 1N NaOH until you have clear solution
add 10 mL PBS 10x
adjust the volume to 100 mL
aliquote and freeze

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And don't forget not to thaw and refreeze So aliquot into required volumes

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i make it up fresh every time i need it as it tends to degrade

0.4g in 10ml pbs in universal tube (loose lid) in a beaker to stop it falling over

microwave 10sec, mix, 10sec, mix, 10sec, mix

add 2ul 5M Naoh

tighten lid and put ice in the beaker to cool it down

(also dont breath in fumes from microwave)

dom

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Stupid question from me too. .. looking at the title of the post. .

Is solution of Paraformaldehyde called so or does it become Formaldehyde when U put it in water?

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soln = formaldehyde

powder = paraformaldehyde

(i think it was mdfenko - who explained it in detail in another thread)

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You could also buy formaldehyde from sigma for immunostaining. Its 37% solution and I use it at 3.7% for fixing cells.

I only make up fresh PFA for perfusing animals.

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paraformaldehyde is solid i think. formaldehyde mostly available as 37-50% solution and formalin is a solution of formaldehyde in water.

or so

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wasn't me.

i read it, didn't write it (it was perneseblue).

here it is:

paraformaldehyde and formaldehyde

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thanks md (and pernesseblue)

formalin is 40% formaldehyde and is the pathology standard in hospitals

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