SepMate™ is a tube that facilitates the isolation of PBMCs or specific cell types by density gradient centrifugation. SepMate tubes contain an insert that provides a barrier between the density gradient medium and blood. SepMate eliminates the need for layering of blood onto the density gradient medium, and allows for harvesting of the isolated mononuclear cells with a pour. SepMate is also compatible with RosetteSep™ enrichment cocktails, allowing isolation of specific cell types in less than 30 minutes.