Hi!

In my lab we work with density gradients (mostly Nycodenz) a lot to isolate mostly liver NPCs.

But I´ve had quite a bit of trouble to understand how exactly that works.

While I get that the substance (Percoll/Nycodenz/Optiprep and others) has a certain density and lets cell of a certain size pass through and others not, how do you know which cells you target with which concentration and how does the layering of different substances (e.g. Percoll and Nycodenz) help with this?

Can any of you recommend papers that explain the considerations taken when deciding upon the concentration of a medium and how to know what concentration to use and what cell/cell-size it is necessary for?

Or can any of you explain the process a bit more in-depth?

Thank you so much!