Method and apparatus for purifying nucleic acids and performing polymerase chain reaction assays using an immiscible fluid

A method of conducting an assay, the method comprising:

• incubating nucleic acids, beads, and a lysis buffer to form complexes in an incubation chamber, individual ones of the complexes comprising a plurality of nucleic acids and a bead;
• transporting the plurality of complexes through an immiscible fluid in an immiscible fluid chamber into a density medium in a polymerase chain reaction (PCR) chamber, wherein said density medium contains PCR components, wherein said density medium has a density greater than said immiscible fluid but lower than said complexes, wherein the immiscible fluid chamber in fluid communication with the incubation chamber, and wherein the PCR chamber is in fluid communication with the immiscible fluid chamber;
• and
• thermocycling the plurality of complexes, density medium, and PCR components in the PCR chamber to perform PCR on said nucleic acids in the density medium.