The 5' M.R.S Linker sequence is designed for use with any of the 3' miRNA cloning linkers. The sequence has been optimized for linking to the 5' end of RNAs containing a 5' phosphate group. The reaction is carried out with T4 RNA Ligase in the presence of 1 mM ATP. The sequence contains restriction endonuclease recognition sites compatible with Ban 1 (Linker 1), Sty I and Ava I (Linker 2) and EcoRI (Linker 3). Upon reverse transcription of doubly-linked RNAs, the restriction endonuclease appropriate for the 3' cloning linker will also generate compatible ends in the 5' M.R.S Linker sequence permitting concatamerization and/or cloning. Further, the additional restriction sites in the M.R.S Linker, when matched with specific 3' linkers can generate ends for directional cloning. For example, M.R.S Linker/Linker 3 digestion with EcoRI and Ban I will leave a Ban I 5' end and an EcoRI 3' end.