Method and device to fractionate stem cells

A method for the fractionation of adherent stem cells from a living cell sample, comprising the following steps:

• a) preparing said living cell sample containing adherent stem cells suspended in a biocompatible fluid which is a mobile phase of a fractionation device;
• b) introducing said living cell sample into the fractionation device to perform non-equilibrium, gravity-assisted dynamic fractionation, wherein said introducing step is performed by a continuous flow of said mobile phase in a direction that is coincident with the direction of the Earth gravity field;
• wherein said continuous flow rate value is such that the injected cells present in said sample do not sediment at the accumulation wall of said fractionation device;
• c) eluting a plurality of sample fractions from said fractionation device wherein the fractionation channel is held in a horizontal position to make the gravitational field act perpendicularly to the carrier liquid flow;
• wherein said eluting step is performed at a mobile phase flow rate value for which the cells present in said sample do not come in contact with a wall of said fractionation device;
• and wherein said eluting step is performed at a mobile phase flow rate value for which the cells of said sample are swept down the channel at a given distance from said walls of said fractionation device;
• wherein in said step b) and in said step c) said introducing step and said eluting step are performed without stopping the flow, and at a flow rate value for which the cells present in said sample are not in contact with the accumulation wall;
• d) collecting fractions containing said stem cells from said plurality of sample fractions to produce fractionated stem cells.