A system for rapidly detecting the presence of an infectious agent in a biological sample, while minimising damage to living, engineered B- lymphocytes and minimising any bubbling of a mixed biosensor reagent and biological sample in a reaction chamber, comprising: a. a single biosensor reagent including at least one antibody specific for a predetermined infectious agent and a bioluminescent agent, the biosensor reagent being operative to: (i) detect the presence of a specific infectious agent in a biological sample to be tested, and (ii) emit a detectable light signal when the biosensor reagent reacts with the biological sample and detects the presence of the specific infectious agent in the biological sample; b. a single-use, disposable test cartridge including: (i) a reservoir card, wherein the reservoir card further includes the biosensor reagent; and (ii) a test cartridge base, wherein the test cartridge base is configured to accept the reservoir card; and c. a testing unit adapted to receive the single-use disposable test cartridge, the testing unit including a sensor for detecting the detectable light signal emitted by the biosensor reagent upon reacting with the biological sample, the detection of the emitted detectable light signal being indicative of the presence of the infectious agent in the biological sample and being the only analysis of the emitted detectable light signal that is performed, wherein detection of the specific infectious agent in the biological sample occurs in real time; characterized in that: the at least one antibody is expressed on the surface of living, engineered B-lymphocytes and the bioluminescent agent is aequorin expressed by the living, engineered B-lymphocytes; and the test cartridge base further includes: (a) a reaction chamber having a central axis, wherein the reaction chamber has the shape of a revolved half ellipse; (b) an inlet channel connected to the reaction chamber, wherein the inlet channel is positioned above the reaction chamber at an angle of 15-60 degrees above the horizontal, and wherein the inlet channel is offset from the central axis of the reaction chamber, adapted such that upon introducing the biological sample into the test cartridge base through the inlet channel, the biological sample is homogeneously mixed with the biosensor reagent. a. a single biosensor reagent including at least one antibody specific for a predetermined infectious agent and a bioluminescent agent, the biosensor reagent being operative to: (i) detect the presence of a specific infectious agent in a biological sample to be tested, and (ii) emit a detectable light signal when the biosensor reagent reacts with the biological sample and detects the presence of the specific infectious agent in the biological sample; b. a single-use, disposable test cartridge including: (i) a reservoir card, wherein the reservoir card further includes the biosensor reagent; and (ii) a test cartridge base, wherein the test cartridge base is configured to accept the reservoir card; and (i) a reservoir card, wherein the reservoir card further includes the biosensor reagent; and (ii) a test cartridge base, wherein the test cartridge base is configured to accept the reservoir card; and c. a testing unit adapted to receive the single-use disposable test cartridge, the testing unit including a sensor for detecting the detectable light signal emitted by the biosensor reagent upon reacting with the biological sample, the detection of the emitted detectable light signal being indicative of the presence of the infectious agent in the biological sample and being the only analysis of the emitted detectable light signal that is performed, wherein detection of the specific infectious agent in the biological sample occurs in real time; the at least one antibody is expressed on the surface of living, engineered B-lymphocytes and the bioluminescent agent is aequorin expressed by the living, engineered B-lymphocytes; and the test cartridge base further includes: (a) a reaction chamber having a central axis, wherein the reaction chamber has the shape of a revolved half ellipse; (b) an inlet channel connected to the reaction chamber, wherein the inlet channel is positioned above the reaction chamber at an angle of 15-60 degrees above the horizontal, and wherein the inlet channel is offset from the central axis of the reaction chamber, adapted such that upon introducing the biological sample into the test cartridge base through the inlet channel, the biological sample is homogeneously mixed with the biosensor reagent.