Fluidic systems including cartridges with modular components (cassettes) and/or microfluidic channels for performing chemical and/or biological analyses are provided. The systems described herein include a cartridge comprising, in some embodiments, a frame, one or more cassettes which may be inserted into the frame, and a channel system for transporting fluids. In certain embodiments, the one or more cassettes comprise one or more reservoirs or vessels configured to contain and/or receive a fluid (e.g., a stored reagent, a sample). In some cases, the stored reagent may include one or more lyospheres. The systems and methods described herein may be useful for performing chemical and/or biological reactions including polymerase chain reactions (PCR) such as those performed within a laboratory, clinical (e.g., hospital), or research setting.