Quite a few miRNAs, like identified placenta-specific miRNAs, the expression patterns differedBackground: Acute lymphoblastic leukemia (ALL) may be the most common pediatric malignancy. You will find roughly 60 new ALL instances per year in Hungary. Extracellular vesicles containing microRNAs are in great interest of scientific research. Their function is just not fully understood, especially not in pediatric leukemia. Altered microRNA expression pattern is established in several malignant conditions. The aim of this study was to identify a set of microRNAs associated with pediatric ALL and its genetic subgroups. Approaches: Platelet-free plasma samples were obtained from 16 newly diagnosed de novo and five relapsed pediatric ALL sufferers and 10 healthy controls. RNA isolation was carried out employing MMP-7 Proteins Molecular Weight Qiagen miRNeasy Serum/Plasma Kit. Quantification of 46 candidate miRNAs was performed making use of Custom TaqMan Advanced Low Density miRNA Array Card. Outcomes: The expression of 19 microRNAs showed considerable difference when comparing ALL and wholesome control platelet-free plasma samples (p 0.05). miR-128-3p, miR-181b-5p and miR-222-3p elevated most significantly in ALL samples. No distinction was located in microRNA levels of hyperdiploid, ETV6/ RUNX1 fusion-positive and normal karyotype ALL individuals. Summary/Conclusion: Determined by the literature, the function of miR-128 and miR-181 family members is recognized in typical lymphopoiesis, which can explain the background of our findings. Tumour suppressor gene TP53 as a target of certain microRNAs like miR-222 may possibly take a part of the improvement of leukemia. Circulating microRNAs may possibly serve as biomarkers for pediatric ALL. Funding: This study was supported by the National Investigation, Improvement and Innovation Workplace (NKFIH) K115861.ISEV 2018 abstract bookPF06: Novel Developments in EV Isolation Chairs: Carmen Fernandez; Felix Royo Location: Exhibit Hall 17:158:PF06.Characterization of RNA contained in extremely purified exosomes from foetal bovine serum Filiberto A. Bautista-Moreno; Mariana Flores-Torres; Selma Er dira Avenda -Vazquez; C. Fabi Flores-Jasso2 Instituto Nacional de Medicina Gen ica, Ciudad de M ico, MexicoBackground: Lately, Krichevsky’s lab described the classes of RNA contained within a foetal bovine serum (FBS) by separating vesicular and non-vesicular fractions and concluded that extracellular vesicles (EVs) could mediate microRNA transfer into cell cultures potentially biasing the outcomes of small RNA detection. Just before deep-sequencing, the RNA was isolated from exosome pellets obtained by ultracentrifugation. However, it can be been widely shown that ultracentrifugation pellets are very contaminated by non-vesicular proteins, a number of which potentially include members of Argonaute family members and cognate microRNAs. The drawback of using ultracentrifugation as sole process to isolate exosomes is the fact that it might drag down non-vesicular proteins, difficulting final results interpretation. We aimed to get a extremely pure EVs fraction to be able to characterize the RNAs present in that fraction and evaluate it together with the RNA contained within the whole FBS. Approaches: To cope with this dilemma, we isolated the EVs employing a combination of pre-existing procedures. Very first, we used a size-exclusion chromatography, followed by an ultrafiltration with 100-KDa filters, which concentrate the samples and realize to remove the proteins smaller sized than one hundred KDa. Then, we performed a Caspase-6 Proteins web precipitation with the EVs employing the Vn96 peptide, which has affinity for the heat-shock.