Enhancement of resolution of low molecular weight RNA profiles by staircase electrophoresis.

Stable low molecular weight (LMW) RNA comprises molecules used in the taxonomy of microorganisms and in studies on the microbial diversity of populations. However, the use of electrophoretic techniques has been hampered due to the low resolution obtained with techniques used for the separation of this kind of molecule. In this work we develop an electrophoretic method (staircase electrophoresis) that increases the resolution of the technique. This improvement in the resolution adequately resolves the three zones that integrate the profiles of LMW RNA: ribosomic 5S RNA (5S rRNA), class 2 transfer RNA (tRNA), and class 1 transfer RNA, allowing the technique to be applied to taxonomic studies (diagnostic, the identification of the individuals), phylogenetic studies and studies on naturally occurring microbial populations.