System for thermocycling of fluids in cartridges

A system for thermocycling of fluids in cartridges comprising

• a) a cartridge with at least one heat conducting wall and at least one light transparent wall, the cartridge having a fluid inlet and a fluid outlet which are connected by a channel, said cartridge having a protrusion into the channel, such that the channel is longer than the shortest distance between the fluid inlet and the fluid outlet to allow bubble-free flow-through filling of the cartridge, wherein the fluid inlet is directly connected to a top wall, a bottom wall, and a pair of sidewalls, wherein the side walls form an angle of 100°-150° with the walls of the fluid inlet, and wherein the fluid outlet is directly connected to the top wall, the bottom wall, and a pair of side walls, wherein the side walls form an angle of 100°-150° with the walls of the fluid outlet,
• b) a thermocycling unit in thermal contact with said heat conducting wall of said cartridge,
• c) a light source for transmitting light into the interior of said cartridge through said light transparent wall of said cartridge which is arranged substantially perpendicular to said heat conducting wall,
• d) a light detector for detecting light emerging from the interior of the cartridge through said light transparent wall,
• e) a fluid providing unit coupled to an inlet of the cartridge for providing the cartridge with fluid by flow-through-filling.