A microfluidic cartridge having a microfluidic channel may have at least one surface that has been roughened, etched or otherwise treated to alter its surface characteristics. In some instances, a microfluidic cartridge may have a microfluidic channel that is configured to provide even distribution of a lysing reagent across the channel. The surface may be roughened or etched using a laser, an abrasive, application of a solvent or in any other suitable manner.