A microfluidic apparatus, method, and associated applications utilize and apply to a formalin-fixed paraffin-embedded (FFPE) tissue sample and performing a liquid-liquid extraction to remove the paraffin from the tissue sample prior to a nucleic acid purification step. A microfluidic device includes a dedicated liquid-liquid extraction process vessel, a nucleic acid purification process component, and a nucleic acid amplification reactor. A liquid-liquid extraction and nucleic acid purification kit includes a microfluidic device capable of performing both a liquid-liquid extraction process and a nucleic acid purification process, including a dedicated liquid-liquid extraction process vessel, an immiscible liquid or a precursor phase thereof disposed in the vessel, a nucleic acid purification process component, a nucleic acid amplification reactor fluidically, and a supply of reagents suitable to enable the liquid-liquid extraction process and the nucleic acid purification process.