Stability of Thrombin 29mer in Different Environments

Science Center, Bent Corridor

Ovarian cancer is the fifth leading cause of cancer-related death among women and is also one of the deadliest gynecologic cancers, affecting 1 in 75 women. The purpose of testing the stability of the 29mer thrombin aptamer is to find a detection method to ovarian cancer. The thrombin aptamer acts as a model system for what an aptamer interacting with a protein should do, in hopes that knowledge from this could be applicable to aptamers that bind to ovarian cancer, proteins such as CA125.In this experimentation, I will investigate the stability of the 29mer aptamer in different environments of increasing complexity: water, tg (tris-glycine), tgk(tris-glycine-potassium), tgkm(tris-glycine-potassium-magnesium), tgm(tris-glycine-magnesium),10% serum and serum. By evaluating the aptamer in these different environments, the capability of the aptamer to be utilized in the human body will be discovered. This investigation will involve absorbance measurements at 260nm, a wavelength characteristic of DNA, on a small-volume spectrophotometer(Nanodrop). If the 29mer thrombin DNA aptamer in our sample is degrading, then the absorbance values will decrease over time. Throughout this experiment there was a blanking process before each buffer was tested; the blanking process was used to subtract out the absorbance of the solvent from each sample measurement This blanking however may have led to discrepancies because the blanking was done with water, which has a very low absorbance in comparison to the absorbance of the solvents that were used on the buffer systems. In conclusion of this experiment, we noticed there were no discernable patterns within the different environments. This study could be extended through the usage of different blanking methods with the same environments.