Discussion
In the present study, miRNA profile isolated from blood serum
exosome samples with ExoQuick™ Exosome Precipitation Solution
was compared to conventionally used ultracentrifugation method. To
our knowledge, although the overall exosomal miRNA yields obtained
from serum have been addressed [4,7] this is the first study where
serumexosomalmiRNA content is compared between the exosomeisolation
methods. Alvarez et al. have studied protein, miRNA and mRNA
levels using different methods for the isolation of urinary exosomes
[9],where the highest exosome yield and RNA quantitieswere obtained
by using a modified ExoQuick based method, while for protein analysis
ultracentrifugation methods were found to be more suitable. Larger
panel ofmiRNAs was investigated in our study, still, our results are concordant
showing that similar to urine samples, higher miRNA yield in
serum exosomes was detected by ExoQuick method. This could be explained
with technical differences between the exosome isolation