A cartridge for processing a sample of a biological fluid such as blood, blood plasma, saliva, urine or other bodily fluid of a subject, said cartridge comprising an injection molded base part and a cover on top of the base part, wherein a micro-fluidic system is generated in the surface of the base part during injection molding, wherein the base part is hydrophilized to give it a low contact angle that enable capillary flow, the micro-fluidic system comprising: - an intake port through which the sample can be placed in; - a processing chamber in which processing of the sample can take place; - a storage chamber in which the sample can intermediately be stored, having a storage capillary suction pressure (p c), wherein the storage chamber is connected by a venting channel to a first vent port that allows for escape of air from the storage chamber; - an intake capillary channel that connects the intake port to the storage chamber, having an intake capillary suction pressure (p B), the intake capillary suction pressure (p B) and the storage capillary suction pressure (p c) are sufficiently high to drive some sample from the intake port to the storage chamber without need of any additional pressure; - a feeding capillary channel that connects the storage chamber to the processing chamber, the feeding capillary channel having a feeding capillary suction pressure (p D); wherein the feeding capillary suction pressure (p D) is sufficiently high to drive some sample from the storage chamber to the processing chamber, and wherein the storage capillary suction pressure (p c) is lower than the feeding capillary suction pressure and the processing chamber suction pressure (p D); - a flow control element (18, 20), said flow control element being a vent which is configured and adapted to be controllably opened such that the sample can be drawn from the storage chamber towards the processing chamber without any active pumping, wherein the flow control element is further adapted to prevent the sample to go to the processing chamber when the sample is entered into the cartridge via the intake port and directed to the storage chamber, although p C is lower than p D; wherein the intake capillary channel and the feeding capillary channel have a common portion of channel which serves both as for the intake of the sample to the storage chamber and as for the feeding of the processing chamber; and wherein the portion of feeding capillary channel which is not in common with the intake capillary channel branches from the intake capillary channel. - an intake port through which the sample can be placed in; - a processing chamber in which processing of the sample can take place; - a storage chamber in which the sample can intermediately be stored, having a storage capillary suction pressure (p c), wherein the storage chamber is connected by a venting channel to a first vent port that allows for escape of air from the storage chamber; - an intake capillary channel that connects the intake port to the storage chamber, having an intake capillary suction pressure (p B), the intake capillary suction pressure (p B) and the storage capillary suction pressure (p c) are sufficiently high to drive some sample from the intake port to the storage chamber without need of any additional pressure; - a feeding capillary channel that connects the storage chamber to the processing chamber, the feeding capillary channel having a feeding capillary suction pressure (p D); wherein the feeding capillary suction pressure (p D) is sufficiently high to drive some sample from the storage chamber to the processing chamber, and wherein the storage capillary suction pressure (p c) is lower than the feeding capillary suction pressure and the processing chamber suction pressure (p D); - a flow control element (18, 20), said flow control element being a vent which is configured and adapted to be controllably opened such that the sample can be drawn from the storage chamber towards the processing chamber without any active pumping, wherein the flow control element is further adapted to prevent the sample to go to the processing chamber when the sample is entered into the cartridge via the intake port and directed to the storage chamber, although p C is lower than p D; wherein the intake capillary channel and the feeding capillary channel have a common portion of channel which serves both as for the intake of the sample to the storage chamber and as for the feeding of the processing chamber; and wherein the portion of feeding capillary channel which is not in common with the intake capillary channel branches from the intake capillary channel. wherein the intake capillary channel and the feeding capillary channel have a common portion of channel which serves both as for the intake of the sample to the storage chamber and as for the feeding of the processing chamber; and wherein the portion of feeding capillary channel which is not in common with the intake capillary channel branches from the intake capillary channel.