Microfluidic system and method for isolating and quantifying at least one sub-population of cells from a population of cells

A microfluidic system configured to receive populations of cells and configured to simultaneously isolate and quantify for each of said populations at least one sub-population of cells expressing a first marker having affinity for a second substance, said system including a substrate in which is etched a network of microchannels comprising a first sorting unit comprising magnetic trapping means to isolate by magnetic attraction magnetic microbeads bound to cells of interest of said population of cells in at least one first sorting microchannel,

• said network comprising a second simultaneous sorting and counting unit including at least one second sorting microchannel which directly or indirectly communicates with said at least one first sorting microchannel and which is defined by a closed wall having an internal face intended to be in contact with said cells of interest bound to said magnetic microbeads, said internal face being provided with at least one pair of electrodes functionalized with said second substance to specifically trap said sub-population of cells from among said cells of interest bound to said magnetic microbeads,
• said second sorting and counting unit including counting means by electrochemical impedance spectroscopy of said or each sub-population trapped on said pair of electrodes,
• wherein said at least one pair of said electrodes laid out facing each other on two opposite sides of said internal face, and with at least one associated pair of second electrically powered trapping micro-coils which are configured to bring said cells of interest bound to said magnetic microbeads in close contact with said electrodes, which are laid out in said wall and facing said respective electrodes to command successive and alternating attraction and release cycles between the micro-coils of said at least one pair of second micro-coils.