Northern Blot Analysis of Plant MicroRNAs and Other Small RNAs

The study of regulatory small RNAs, such as siRNAs and microRNAs in plants and other organisms, has necessitated techniques tailored to their unique features. Their analysis requires the use of sensitive and quantitative methods for their detection. The use of northern blot hybridization offers an attractive approach to address qualitative as well as quantitative features, and we describe here the use of radioactive and nonradioactive methods for signal detection. We highlight the advantages and shortcomings of these approaches and offer a detailed description of the techniques that best work for us, considering their use for the study of various small RNAs in multiple samples. We list relevant details and provide cautionary comments in those steps where we have detected potential difficulties.