Abstract: The technology described herein generally relates to microfluidic cartridges. The technology more particularly relates to a compressible pad applied to a microfluidic cartridge, wherein the microfluidic cartridge is configured to amplify nucleotides of interest, particularly from several biological samples in parallel, within microfluidic channels in the cartridge and permit detection of those nucleotides. Compressible pads of the present technology can be implemented in microfluidic cartridges having enhanced reaction chamber volumes, resulting in improved thermal uniformity and amplification efficiency in the cartridge. Assays using microfluidic cartridges of the present technology advantageously exhibit improved limit of detection (LOD) and improved limit of quantification (LOQ).