Abstract: In some aspects, a system is disclosed for detecting genetic targets for diagnosing tuberculosis and associated antibiotic resistance. The system includes a mechanical instrument and a cartridge assembly. The cartridge assembly comprises one or more reservoirs, with at least one reservoir containing a wet reagent. The cartridge also includes a chip with a fluidic channel holding a liquid slug. The chip has an optical detection region positioned between a heating region and a cool region. The mechanical instrument controls the back and forth motion of the liquid slug between the heating and cool regions. Additionally, the cartridge assembly includes one or more puncture elements configured to pierce the reservoirs and provide the wet reagent to the chip. The system further includes an optical detection unit with an optical light-emitting element, an optical detector, and a processing unit for analyzing the optical detection region of the chip.