Product Description
This is a AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A338763. The abstract provided by the Pentagon follows: An in vitro selection methodology (PhotoSELEX) was investigated and used to identify ssDNA aptamers capable of binding with high affinity and capable of covalently cross-linking via a high quantum yield photochemical reaction the human basic Fibroblast Growth Factor (bFGF) protein. Beginning with a library of ssDNA aptamers in which thymidine had been replaced with the chromophore 5-bromo-2'-deoxyuridine, five rounds of affinity-based in vitro selection were completed. The resulting library was then irradiated with 308 nm light in the presence of bFGF. Those sequences capable of forming a covalent bond to the target protein were subsequently partitioned from those not capable of forming such a bond. Enzymatic digestion of the protein component yielded a template suitable for polymerase chain reaction (PCR) amplification permitting additional rounds of such photocross-linking selection. Systematic and exclusive application of rounds of PhotoSELEX on such a library identified ssDNA aptamers with high affinity binding and high quantum yield cross-linking potential for the target. Moreover, it was shown that PhotoSELEX can be manipulated to yield: (1) exceptionally high affinity binding or (2) exceptionally high quantum yield cross-liking aptamers depending on the nature of the pressure applied during the experiment. Based upon these results, a PhotoSELEX experiment was performed in which photochemical and affinity pressure were applied simultaneously to a completely random oligonucleotide library. |
