The number of uncoded (non-coding; nc) RNAs with unknown functions is increasing. Since their first detections especially miRNA of ncRNAs have become very important. In fact, their importance has been well understood and their relations with diseases are more evident. It is clear that they can be used in the diagnosis of most diseases in the future. Northern hybridization, flow cytometry, cloning, qPCR, sequencing and microarray analysis can be used for miRNA detection.