A new blotting medium for the simple isolation and identification of highly resolved messenger RNA.

A simple method has been developed that allows the rapid isolation and identification of highly resolved mRNA molecules. RNA species are separated by gel electrophoresis and then blotted on to a paper sheet to which polyuridylic acid has been covalently bound. This mRNA affinity paper ("mAP") specifically binds, in a reversible manner, polyA+ containing molecules. A replica picture of the agarose gel is thus obtained on the mAP, from which bound mRNA molecules can be eluted by heating in water. In addition to their simple isolation individual mRNA species, whilst still bound to mAP, can be identified by both "in-situ" hybridization and translation.