LncRNAs are present in serum exosomes

There is high interest in discovering and developing useful RNA-based biofluid markers. The RNAs in patient fluids are present in circulating exosomes. Exosomes are 40 - 100 nm membrane vesicles secreted by most cell types in vivo and in vitro. Exosomes are found in blood, urine, amniotic fluid, malignant ascite fluids and contain distinct subsets of microRNAs depending upon the tumor from which they are secreted. We wanted to test whether lncRNAs may be present in circulation exosomes as well by using the LncProfiler qPCR array. We precipitated exosomes from a human pooled serum sample (1ml) using SBI's ExoQuick™ exosome precipitation reagent (cat#EXOQ5A-1). The exosome vesicles were then lysed and the exosomal RNA purified using SBI's SeraMir™. The resulting exoRNA was converted to cDNA using the LncProfiler cDNA synthesis kit. The cDNA was tested in duplicate across all of the LncProfiler qPCR array assay set.