text: The advantage of TEC-RED over SAGE is that no restriction endonuclease is needed for the initial linker binding. This prevents bias associated with restriction site sequences that will be missing from some genes, as is seen in SAGE. The ability to have a snapshot of specific RNA isoforms allows the deduction of differential regulation of isoforms through alternative selection of promoters. This may also aid in the discernment of expression patterns unique to the SL1 or SL2 sequence. TEC-RED also allows characterization of the 5’ ends of RNA produced and therefore of isoforms that differ by the amino terminal splicing. The technology permits the determination and verification of all known and unknown genes that may be predicted as well as the 5’ splice isoforms or 5’ RNA ends that may be produced. Using TEC-RED in conjunction with SAGE or a modified protocol will allow discernment of the 5’ and 3’ ends of transcripts, respectively.  The identification of alternative splice variants, and possibly the relative quantities, containing a trans-spliced leader sequence is therefore possible.