Optimization of purification of human cell-free mRNA from plasma.

Cell-free RNA has a potential for diagnosis and prognosis of many diseases. Our aim was to optimize a commercially available QIAamp UltraSens Virus Kit (Qiagen, Hilden, Germany) for isolation of mRNA from human plasma. The amount of carrier RNA to bind plasma mRNA, the centrifugal force to pellet the mRNA-carrier RNA complex, the incubation time for proteolysis, and the centrifugal force to bind mRNA to the silica gel membrane were modified in order to maximize the yield of isolated mRNA.