The objective of this Phase I project is to test a semi-synthetic approach to protein reverse translation (pRT), reversing the central biochemical dogma that protein can not be converted back into a DNA molecule. To test this novel chemistry, a set of N-terminal specific recognition materials for use in peptide separations and analysis will be selected from an ultra-high complexity RNA aptamer library (5x10¹⁶). As a first step we will focus on making a set of three (3) N-terminus specific recognition modules (RM) that specifically recognize one of the three amino acids found in the commercially available flag tag with sequence NYKNNNNK.