A flow cytometry system comprising: - a measuring cell delimiting at least partially a measuring chamber, - an injection device arranged to inject a flow of biological particles to be analyzed in the measuring chamber, the injection device comprising: - an injection nozzle delimiting an internal chamber and comprising an injection orifice fluidly connected to the measuring chamber, - a first feeding conduit opening into the internal chamber and intended to feed the internal chamber with a liquid sample containing the biological particles to be analyzed, and - a second feeding conduit opening into the internal chamber and intended to feed the internal chamber with a first sheathing fluid, the injection nozzle and the second feeding conduit being configured so that the first sheathing fluid introduced in the internal chamber is capable of hydro-dynamically sheathing the liquid sample introduced in the internal chamber, - an evacuation device arranged to evacuate outside of the cytometry system the flow of biological particles injected in the measuring chamber, - a third feeding conduit fluidly connected to the measuring chamber and intended to feed the measuring chamber with a second sheathing fluid, the measuring chamber and the third feeding conduit being configured so that the second sheathing fluid introduced in the measuring chamber is capable of hydro-dynamically sheathing the flow of biological particles in the measuring chamber, - a measuring set arranged to measure at least one optical property of the biological particles to be analyzed, the measuring set including: - at least one emission device arranged to emit a light beam toward the measuring chamber and capable of crossing the flow of biological particles, the at least one emission device comprising a light source arranged to generate the light beam, - at least one collecting device (43a-43c) arranged to collect light rays coming from the measuring chamber, characterized in that the flow cytometry system further comprises a reference support which is in one-piece and on which the injection device, the evacuation device, the at least one emission device and the at least one collecting device (43a-43c) are mounted, in that the reference support delimits a receiving housing in which the measuring cell is housed, the measuring cell being fluidly isolated from the receiving housing, and in that the injection and evacuation devices (12, 13) are respectively fastened on two opposite external faces of the reference support, the evacuation device being mounted on the reference support opposite to the injection device with respect to the measuring cell. - a measuring cell delimiting at least partially a measuring chamber, - an injection device arranged to inject a flow of biological particles to be analyzed in the measuring chamber, the injection device comprising: - an injection nozzle delimiting an internal chamber and comprising an injection orifice fluidly connected to the measuring chamber, - a first feeding conduit opening into the internal chamber and intended to feed the internal chamber with a liquid sample containing the biological particles to be analyzed, and - a second feeding conduit opening into the internal chamber and intended to feed the internal chamber with a first sheathing fluid, the injection nozzle and the second feeding conduit being configured so that the first sheathing fluid introduced in the internal chamber is capable of hydro-dynamically sheathing the liquid sample introduced in the internal chamber, - an injection nozzle delimiting an internal chamber and comprising an injection orifice fluidly connected to the measuring chamber, - a first feeding conduit opening into the internal chamber and intended to feed the internal chamber with a liquid sample containing the biological particles to be analyzed, and - a second feeding conduit opening into the internal chamber and intended to feed the internal chamber with a first sheathing fluid, the injection nozzle and the second feeding conduit being configured so that the first sheathing fluid introduced in the internal chamber is capable of hydro-dynamically sheathing the liquid sample introduced in the internal chamber, - an evacuation device arranged to evacuate outside of the cytometry system the flow of biological particles injected in the measuring chamber, - a third feeding conduit fluidly connected to the measuring chamber and intended to feed the measuring chamber with a second sheathing fluid, the measuring chamber and the third feeding conduit being configured so that the second sheathing fluid introduced in the measuring chamber is capable of hydro-dynamically sheathing the flow of biological particles in the measuring chamber, - a measuring set arranged to measure at least one optical property of the biological particles to be analyzed, the measuring set including: - at least one emission device arranged to emit a light beam toward the measuring chamber and capable of crossing the flow of biological particles, the at least one emission device comprising a light source arranged to generate the light beam, - at least one collecting device (43a-43c) arranged to collect light rays coming from the measuring chamber, - at least one emission device arranged to emit a light beam toward the measuring chamber and capable of crossing the flow of biological particles, the at least one emission device comprising a light source arranged to generate the light beam, - at least one collecting device (43a-43c) arranged to collect light rays coming from the measuring chamber,