A microfluidic device comprising: a micro fluidic resistance network comprising a micro fluidic sample preparation stage, a sample output and a separate waste output both in fluidic communication with said preparation stage; and a measurement chip for use with the separate microfluidic resistance network , the measurement chip comprising: a sample channel extending between a sample inlet for receiving a sample stream from said network and a sample outlet , the sample channel comprising measurement means and having a first fluidic resistance; and a waste channel extending between a waste inlet for receiving a separate waste stream of said sample from said network and a waste outlet, said waste channel having a second fluidic resistance, wherein the sample channel and the waste channel have been formed in the same manufacturing process, and wherein the ratio between the first fluidic resistance and the second fluidic resistance is predefined to ensure a predetermined flow rate through the sample channel, wherein the micro fluidic resistance network and the measurement chip are manufactured separately, and wherein the sample channel is in fluidic communication with said sample output and the waste channel is in fluidic communication with said separate waste output . a micro fluidic resistance network comprising a micro fluidic sample preparation stage, a sample output and a separate waste output both in fluidic communication with said preparation stage; and a measurement chip for use with the separate microfluidic resistance network , the measurement chip comprising: a sample channel extending between a sample inlet for receiving a sample stream from said network and a sample outlet , the sample channel comprising measurement means and having a first fluidic resistance; and a waste channel extending between a waste inlet for receiving a separate waste stream of said sample from said network and a waste outlet, said waste channel having a second fluidic resistance, wherein the sample channel and the waste channel have been formed in the same manufacturing process, and wherein the ratio between the first fluidic resistance and the second fluidic resistance is predefined to ensure a predetermined flow rate through the sample channel, wherein the micro fluidic resistance network and the measurement chip are manufactured separately, and wherein the sample channel is in fluidic communication with said sample output and the waste channel is in fluidic communication with said separate waste output . a sample channel extending between a sample inlet for receiving a sample stream from said network and a sample outlet , the sample channel comprising measurement means and having a first fluidic resistance; and a waste channel extending between a waste inlet for receiving a separate waste stream of said sample from said network and a waste outlet, said waste channel having a second fluidic resistance, wherein the sample channel and the waste channel have been formed in the same manufacturing process, and wherein the ratio between the first fluidic resistance and the second fluidic resistance is predefined to ensure a predetermined flow rate through the sample channel, wherein the micro fluidic resistance network and the measurement chip are manufactured separately, and wherein the sample channel is in fluidic communication with said sample output and the waste channel is in fluidic communication with said separate waste output . <EOS>