10 June 2013

1. We decided to repeat Electric Mobility Shift Assay with different concentrations of CEA protein and DNA aptamers. We decided to take Protein:DNA ratio as 1:5, i.e. 2 ul of protein to 10 ul of DNA.

2. DNA aptamers from SELEX 7 were amplified with PCR and checked with PAGE. However, no bands appeared for DNA. We decided to repeat the amplificatiion.

3. On the meeting, at the end of the day, we presented two new modified ideas on making biosensors. The first idea was about using yeast to express streptavidin on its cell surface and then to attach biotinalated aptamer to it, then add CEA, and finally to add the aptamer with fluorophore which will confirm the presence of the CEA. The second idea was similar, but with using E.Coli, which will express the streptavidin on the outer membrane.

4. Detailed protocols for both ideas will be provided on Wednesday, June 12.