MicroRNAs (miRNAs) are stably present in circulatory systems. They are bound to various carriers like proteins, lipoprotein particles, and exosomes. Investigating the process of miRNA distribution among these carriers will help improve our understanding of their functions in the extracellular environment and their potential relationship with diseases. Here, researchers from the University of California, Riverside describe how to obtain the distribution profiles of circulating miRNAs by separation of different miRNA carriers in human serum with asymmetrical flow field flow fractionation (AF4), and detection of the miRNAs in the eluted fractions that enrich particular types of carriers with RT-qPCR.
The optimized flow rates should separate HDL and LDL well, and LDL and exosome could have some overlap
(a) Separation of pooled healthy male AB serum and exosome extract stained with DiO for fluorescence detection of lipophilic species; (b) Separation of pooled serum and pooled serum spiked with HDL or LDL with absorbance detection at 260 nm