Has anyone worked on separation of Argonaute proteins from HDL in plasma, so that RNA binding is not disturbed (with the final goal of sequencing RNAs bound to each)? A simple method would be preferable. IP is last resort. Size exclusion (GE Healthcare) - the setup is precise, but columns and setup too expensive. 100K Ultracel filters do not seem to work. Optiprep density gradient (5-25-30%) densities with bottom loading leaves an overlap between protein fraction & HDL fraction.