Analysis of the methylated 'cap' structures of vaccinia mRNA by two-dimensional thin-layer chromatography.

Two different twodimensional cellulose thinlayer separations for blocked, methylated mRNA 5'-termini are described. They allow rapid analysis even of complex mixtures of mRNA "cap" structures on the basis of their methyl group content and base composition. These simple procedures are especially useful for the analysis of [3H-methyl]-labeled mRNA in combination with tritium fluorography. A qualitative and quantitative analysis of the methylated "cap" structures of in vitro labeled Vaccinia "core" mRNA is presented. The presence of methylated "cap" structures in Vaccinia RNA increases the in vitro translation efficiency of methylated Vaccinia RNA over Vaccinia RNA transcribed in the absence of a methyl group donor.