Ilum has tons of nodes scattered all around it for Bioanalysis, but unlike Scavenging, Slicing and Archaeology I'd have to argue that Ilum isn't by far the best possible place to farm Bioanalysis materials. I'd say that Belsavis (the bonus series section at least) has equally as many Bioanalysis materials as Ilum. If you'd like to see my Bioanalysis guide for Belsavis click here. However, this guide of course is for Ilum and you will still find a ton of materials here even with four or five people farming here you'll still be able to get your fair share of materials.
The key to finding a lot of Bioanalysis materials is going to places without a lot of Humanoid monsters. Usually areas outside of "encampments" are where you will find the most materials to harvest.
This path was originally made and tested for Archaeology but it seems as if it is useful for more than just farming Archeology nodes. Along this same path I found just as many Slicing, Bioanalysis and Scavenging nodes as I did Archaeology nodes. It is literally like a line of candy, it's just node after node after node and it's a never ending chain. Despite the video being made for Archaeology originally, this video here shows you this exact farming path.
Very few alterations are made in the video depending on if I see a node way off the path (then usually see another, it's like a line of candy...) But the idea is to follow the path a wee bit south, wrap around and follow it way up north into Imperial territory. Everything is friendly to you up here... Aside from the Imperials... Wrap around the western side first then come back down the east.
Once you mesh back down into the first line cut over west and up and go around the circular area far northwest. This is a friendly zone with tons of nodes around it and also a chest you can farm. To read more about this chest and how positively awesome it is click here. Below is a list of all the materials you will be gathering on Ilum with Scavenging. Next to each item is the amount I recieve normally with each farming pass and how much I can sell them for.
Psychoactive Compound (Grade 5 Material)
Red Goo (Grade 6 Material)
Parasitic Microorganism (Grade 5 Material)
Nutrient Gel (Grade 5 Material)
Quick-Growth Agent (Grade 5 Material)
Immunity Cell Culture (Grade 6 Material)
Mutagenic Paste (Grade 6 Material)
Neurochemical Extract (Grade 6 Material)