Mononuclear cells (MCs) from a variety of tissues, predominantly liver, spleen, intestine and bone marrow, have been purified by using a strategy similar to that used for the isolation of these cells from blood, namely sedimentation onto a density barrier. 

This density barrier has commonly been a Nycodenz® solution, usually in the form of one of the ready-made Nycoprep™ solutions; sometimes Nycoprep™ 1.077 [1,2], but much more frequently Nycoprep™ 1.077A [3-8]. 

The former was originally formulated for the isolation of MC from human blood, the latter from rodent blood. Nycoprep™ 1.077A is no longer commercially available but a solution of the same density and osmolality may very easily, be prepared from OptiPrep™ (see Section 3).