Characterizing Three Azides for Their Potential Use as C. elegans Anesthetics

Sodium azide (NaN (3) ) is widely used as an anesthetic in the C. elegans community for studying animal behavior. It is not known whether other azides can function as anesthetics. This is quite important for the C. elegans labs in which NaN (3 ) is not a convenient choice, such as all the labs located in China, where NaN (3) is under tight regulation, and alternative anesthetics need to be characterized. In the present study, we focused on another three azides, potassium azide (KN (3) ), trimethylsilyl azide (TMSA), and diphenyl phosphoryl azide (DPPA), which are not regulated in China. We characterized their performance in chemotactic behavioral assays and buffer-based assays. Our results suggest that KN (3) can immobilize worms as effectively as NaN (3 ) in the above-mentioned assays. Therefore, we recommend KN (3) as a routine anesthetic for C. elegans labs.