Sodium Azide

We, sometimes use Sodium Azide to disable worm movement while doing the phenotypic analysis.

Can sometime tell, how does the sodium azide carry out its function inside the worms body to disable it ?

and how long does it has its effect on the body of worms?


I am not quite sure exactly how it works except that it basically suffocates the worm. I can not use it as it has horrid problems. I lose significant GFP expression because the body totally breaks down.

I used NaAzide, but I realize now that it has such bad effects. I am actually wondering if there is something better to fix with besides paraformaldehyde. I think I am losing a lot of signal using paraformaldehyde. I read the blogs and checked my pH, and it was 7.4.
The GFP signal is bright when I don’t fix, but I can’t see exactly localization patterns without fixing.
I am working with worms at the 2 fold- 3 fold stage. Most members in my lab work on stages before that so I am the first that has to worry about fixing embryos.

Does anyone have suggestions?

Thank you,

See the wikipedia entry for sodium azide to find it’s mechanism of action.

Here is an article which gives an excellent method to fix worms for microscopy without using Azide.

“A rapid nematode preparation for microscopy” at

Hope this helps ;D


Hello. There seem to be a fair number of labs that switch to full on antibody staining protocols using anti-GFP antibodies if they must fix their embryos.