Isolation of specific tRNAs using an ionic-hydrophobic mixed-mode chromatographic matrix.

The coating of a C18-reversed-phase high performance liquid chromatography support (octadecylsilyl-Hypersil) with a tetraalkylammonium salt (methyltrioctylammonium chloride) produces a chromatographic matrix with both ionic and hydrophobic character. Using this material oligonucleotides and tRNAs can be separated with high resolution. The observed resolution is in part due to the apparent lack of diffusion processes occurring during chromatography with this matrix. Some tRNAs can be obtained in high purity from a bulk tRNA mixture after a single chromatographic step. In general it is more efficient to use the matrix as the last step of a purification procedure for a particular tRNA. A two-step procedure is described which allows, in some cases, the isolation of small quantities of specific tRNA isoacceptors.