A microfluidic device for lysing cells in a fluid, the microfluidic device having a supporting substrate, an inlet for receiving fluid containing cells, a lysis section in fluid communication with the inlet, the lysis section having at least one heater for heating the fluid, a reservoir containing a lysis reagent, and, CMOS circuitry between the supporting substrate and the lysis section, the CMOS circuitry being configured for selectively lysing the cells using thermal lysis in the lysis section, chemically lysing the cells using the lysis reagent, or both chemically and thermally lysing the cells using the lysis section and the lysis reagent.