Star Wars: Knights of the Old Republic Message Board  

1) you go to the console with the two tubes.
2) fill the containment (holds 5) 3) transfer from container to injecter (there should be 2 left in the container)
4)empty the injecter and transfer the 2 from container to injector.
5)fill container and transfer to the injector.
you should receive a message saying something like: critical error fuel unstable! or something like that and then a movie clip should play.

p.s. if you inject the poison medpacks and life support packs will increase in price and depending on how the trial goes you will either be executed or banned from Manaan.