This NSFW clip from Species 4 tells you everything you need to know about good laboratory procedures.
First of all, when administering an injection, it's very important to wear fingerless goth-girl gloves, for safety reasons. Also, if you have a forked or barbed tongue, do make sure to extrude it during the injection.
If you put your experimental subjects into some kind of alien pod, do make sure they're naked, and their breasts are pushed up against the translucent portion of the pod.
If there's technobabble, do make sure you have a slumming former Star Trek actor available, with bizarre glued-on facial hair, to speak it. Probably Brent Spiner - or if he's not available, you can always get Dominic Keating.
Don't implant the alien stem cells until you're sure they're at the right point of their evolution. You can tell this with the naked eye. And you'll be able to tell if the alien stem cells are taking over, from all the multiplying eyeballs on your monitor readout.
Don't go running into the laboratory (without any protective gear) once your blonde human-alien hybrid Swedish supermodel has been empowered by the material you "harvested" from your human experimental subject. Or you'll end up tossed through a window, like poor Dominic. [IMDB]