We don't isolate cells regularly from adult liver, so i'm by no means an expert, but I've had okay luck mechanically dissociating liver using a dounce pestle b. Just resuspend in PBS or any old buffer and dounce 10-15 times. If you intend to do facs you'll want to strain the cells through a filter so the machine won't clog. There are probably much better ways but that's what I tried.

Thank you for your answer. But that's what I tried and it didn't work.. When I did the FACS analysis, only 1% of the suspension was entire cells. But thank you!

I think the problem here is that you are working with a dense/compact tissue, I doubt you would ever get all the cells, 1% might actually be a good starting point.  The real questions are: What are you looking for?  Would microscopy be a better tool? Can you pre-treat (cut out the bits you need)?  Can you culture the cells of interest? Normally, (in my experience) the choice tissues for maceration are lymph nodes/spleens/bone marrow, even brain.  All these tissues much less dense than liver.

Thank you for your answer. I tried to get the percentage of immune cells vs hepatic cells. But I think I'm gonna go with microscopy, even if it's not really quantitative. 

Not sure if this will work.... But it might be worth a try. When we make spleen single cell suspensions we use the sterilized frosted glass slide technique. The tissue is placed between the frosted portion of the 2 slides and quickly and carefully  "lightly ground" into a single cell suspension. It is very important to use a Ca++/Mg++ FREE item such as HBSS or PBS with 2%HI FBS to keep the cells happy and from clumping.

Please let me know if you try this, and if it works.

Thanks, Robert