Most bacteria in natural ecosystems form biofilms-a bacterial community, surrounded by a polymer matrix that consists mostly of exopolysaccharides, proteins, and nucleic acids. Extracellular RNA as a matrix component is involved in biofilm formation-the fact that was confirmed by direct detection of extracellular RNA in the biofilm matrix, and by an interruption of the biofilm's structure with RNases. Number of protocols describing isolation of RNA from biofilm matrix are limited and usually involve uncommon equipment and reagents. Here we describe simple method for extracellular RNA isolation from biofilm matrix using basic laboratory reagent and equipment. Key steps of the protocol include separation of matrix and bacterial cells with high ionic solution of NaCl, RNA precipitation with