Antisense peptides, amino acid sequences encoded in the antisense strand of DNA, can interact with significant affinity and selectivity with their corresponding sensepeptides. Experimentally, sense antisense peptide recognition has been observed repeatedly. However, skepticism about the biological relevance of this phenomenon has persisted. This is due in part to the unexpected and somewhat couterintuitive nature of the interaction as well as to its non-universality as an empirical observation. Nonetheless, antisense peptides in several cases investigated so far have been used as immobilized ligands for the succesful affinity chromatographic separation of native (sense) peptides and proteins For example, immobilized antisense peptides corresponding to Arg8-vasopressin (AVP) have been used to separate vasopressin from oxytocin chromatographically as well as to affinity capture AVP-receptor complex. These results, together with improved understanding of the general features of amino acid sequence which drive antisense-sense peptide interactions as well as new ideas for making antisense peptides chimeras, are beginning to suggest improved ways to make antisense-related peptides as affinity agents for separation as well as for other biotechnology applications.