i want to know also if it is better to make extarction to total rna from blood then isolate miRNA from it or it is better to extarct directly miRNA FROM BLOOD
RNA purification kit is advisable but high cost. TRIZOL method is good but the efficiency depends on the time the sample was kept in storage and other factors. In my experience TRIZOL is good if you use fresh blood. To get more answers check : https://www.researchgate.net/post/What_is_the_best_protocol_for_RNA_isolation_from_whole_blood_TRIzol_or_RNA_Isolation_kits