A cartridge reader is configured to carry out a diagnostic test on a fluid sample contained within a fluidic cartridge. The cartridge comprises first, second and third collapsible blisters containing at least one reagent for use in the diagnostic test. The cartridge reader comprises an upper clamp, occupying a fixed position relative to the reader and a lower clamp, movable relative to the upper clamp, and wherein the upper clamp and the lower clamp are configured to receive and hold a fluidic cartridge therebetween. First, second and third blister actuators are mounted on the upper clamp, for aligning with first, second and third collapsible blisters of a fluidic cartridge inserted into the reader. The first, second and third blister actuators are movable relative to the upper clamp, between a first position in which the blister actuators are spaced apart from the collapsible blisters comprised on the fluidic cartridge received between the upper and lower clamps, and a second position in which the blister actuators depress the collapsible blisters, thereby collapsing the blisters and ejecting the reagents contained therein into a channel in the microfluidic cartridge.