The HPLC-purified library containing a central randomized sequence of 45 nucleotides flanked by two 20-nt and 22-nt primer hybridization sites. Initial library was: 59-TCT CGG ACG CGT GTG GTC GG-N45-C TCG CTG CCT GGC CCT AGA GTG-39, forward primer: 59-FAM-TCT CGG ACG CGT GTG 