The invention relates to a system and method for obtaining a cellular fraction enriched with defined cells effective in promoting a defined cellular response from an in vivo cellular sample comprising: a collection tube for collecting a cell suspension (1), an anticoagulant portion (4), a portion of separation gel (3), a first collection syringe for collecting a cell depleted fluid (10), a second collection syringe for collecting the enriched cellular portion (11) and at least one needle (1O) for attaching to each syringe. The system is closable to the atmosphere, further wherein the cell suspension collection tube contains the gel (3) and the anticoagulant (4), the tube is adapted such that, when containing cell suspension and centrifuged after treatment yields separation fractions, a first fraction comprising cellular fluid (6), a second fraction comprises gel layer (3), a third fraction comprises enriched cellular portion (7) on top of the gel layer and a fourth fraction comprises a cell poor portion (8).
