A system comprising a microfluidic cartridge and a diagnostic apparatus for amplifying and carrying out diagnostic analyses on nucleotides from biological samples, wherein:the microfluidic cartridge is a disposable multi-lane microfluidic cartridge containing sample lanes in parallel, the microfluidic cartridge including: a substrate layer having an upper side and an opposed lower side, wherein each of the plurality of sample lanes comprises an independently configured microfluidic network having, in fluid communication with one another: an inlet; a first valve and a second valve; a PCR reactor configured to carry out PCR amplification of nucleotides in a sample; a vent; a first channel leading from the inlet, via the first valve, to the PCR reactor; and a second channel leading from the PCR reactor, via the second valve, to the vent, a laminate layer attached to the lower side of the substrate layer to seal components of the microfluidic network; and a label layer, the upper side of the substrate layer being disposed towards the label layer, the diagnostic apparatus configured to carry out real-time PCR on biological samples in the microfluidic cartridge, the diagnostic apparatus comprising: a reusable instrument platform to actuate on-cartridge operations, detect and analyze the products of PCR amplification in each of the sample lanes separately; a bay configured to selectively receive the microfluidic cartridge; at least one heat source positioned in the bay and coupled to a processor, wherein the at least one heat source is configured to heat individual sample lanes in the microfluidic cartridge, the processor being configured to control application of heat to the individual sample lanes separately; and, a detection system for monitoring fluorescence from biochemical reactions comprising an optical detector, a light source that selectively emits light in an absorption band of a fluorescent dye, and a light detector that selectively detects light in an emission band of the fluorescent dye, wherein the fluorescent dye corresponds to a fluorescent polynucleotide probe or a fragment thereof, wherein the microfluidic cartridge includes a window above the PCR reactor, through which optical detection is permitted, arranged such that the optical detector is situated above the window when the microfluidic cartridge is located in the bay. a substrate layer having an upper side and an opposed lower side, wherein each of the plurality of sample lanes comprises an independently configured microfluidic network having, in fluid communication with one another: an inlet; a first valve and a second valve; a PCR reactor configured to carry out PCR amplification of nucleotides in a sample; a vent; a first channel leading from the inlet, via the first valve, to the PCR reactor; and a second channel leading from the PCR reactor, via the second valve, to the vent, an inlet; a first valve and a second valve; a PCR reactor configured to carry out PCR amplification of nucleotides in a sample; a vent; a first channel leading from the inlet, via the first valve, to the PCR reactor; and a second channel leading from the PCR reactor, via the second valve, to the vent, a laminate layer attached to the lower side of the substrate layer to seal components of the microfluidic network; and a label layer, the upper side of the substrate layer being disposed towards the label layer, the diagnostic apparatus configured to carry out real-time PCR on biological samples in the microfluidic cartridge, the diagnostic apparatus comprising: a reusable instrument platform to actuate on-cartridge operations, detect and analyze the products of PCR amplification in each of the sample lanes separately; a bay configured to selectively receive the microfluidic cartridge; at least one heat source positioned in the bay and coupled to a processor, wherein the at least one heat source is configured to heat individual sample lanes in the microfluidic cartridge, the processor being configured to control application of heat to the individual sample lanes separately; and, a detection system for monitoring fluorescence from biochemical reactions comprising an optical detector, a light source that selectively emits light in an absorption band of a fluorescent dye, and a light detector that selectively detects light in an emission band of the fluorescent dye, wherein the fluorescent dye corresponds to a fluorescent polynucleotide probe or a fragment thereof, wherein the microfluidic cartridge includes a window above the PCR reactor, through which optical detection is permitted, arranged such that the optical detector is situated above the window when the microfluidic cartridge is located in the bay.