2′-fluoropyrimidine anti-calf intestinal phosphatase nucleic acid ligands

A non-naturally occurring nucleic acid ligand to calf intestinal phosphatase (CIP) identified according to the method comprising:

• a) preparing a candidate mixture of nucleic acids;
• b) contacting the candidate mixture of nucleic acids with CIP, wherein nucleic acids having an increased affinity to CIP relative to the candidate mixture may be partitioned from the remainder of the candidate mixture;
• c) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture;
• and
• d) amplifying the increased affinity nucleic acids to yield a mixture of nucleic acids enriched for nucleic acids with relatively higher affinity and specificity for binding to CIP, whereby a nucleic acid ligand of CIP may be identified.