I am selecting DNA aptamers against a his tagged protein using Ni-NTA affinity SELEX and I am having a bit of a problem coming up with the best suitable method for negative selection. I am torn between waiting until I can see evolution in my bound sequences then performing the negative selection or doing it before every incubation step. Suggestions from anyone who has performed affinity SELEX before would be greatly appreciated.
The best material for negative selection will be NI-NTA beads with immobilised polypeptide composed from histidines. Why?
Because your protein is conjugated with his tag (short polypeptide composed from histidine residues) . Using in negative selection Ni-NTA affinity beads with polypeptide composed from histidines, eliminate during selection nucleotides that interacti wtih your affinity system and his tag residues present in your protein.
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Biology