Oligonucleotide encoding strands

Molecular tags overcome the chemical sensitivity and orthogonal protection required by both peptide and oligonucleotide encoding. Two such methods have been developed and applied to the synthesis of both peptide and nonoligomeric libraries. One of these [34] approaches uses chemically robust haloaromatic tags which are used in a binary encoding 

The encoding tags are halophenoxy derivatives of aliphatic alcohols and are attached to either a photolabile linker as a carbonate or an oxidatively cleavable linker as an ether. The photolabile linker/tag complex is especially well suited to encode peptide libraries through attachment to approximately 1% of the amino groups of each amino acid synthon at eachstage of the synthesis. For structure determination, the tags are released by photolysis at 360 nM. 

The oxidatively cleavable linker/tag complex has broader application and is introduced into the polymeric support by a rhodium-catalyzed carbene insertion. The tags are liberated from the solid support by treatment with ceric ammonium nitrate. For analysis the released tags are first silylated and then separated by gas chromatography. Since the tags are electrophoric, they can be analyzed in subpicomole quantity by electron capture detection. The structure of the compound is deduced from the resulting chromatogram. 

It is not only the ease of introduction, facile detachment, rapid determination and straightforward interpretation that makes these electrophoric encoding molecules so useful, but also the chemical stability of the tags. This stability toward reactants and 

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One of the earliest types of chemical encoding was the attachment of oligonucleotides (usually single-strand DNA)... 

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