I have this issue with drying short DNA fragments on mica for AFM experiment.
As you can see DNA in this AFM image DNA has a preference to face in a certain direction.
I think it was caused by solution drying with nitrogen gas gun. Nitrogen gas perhaps pushes away the solution in a direction along with DNA.
How can I avoid this orientation skewness?
Dear Kim,
in my opinion besides the drying flow the surface charge orientation of the mica might be considered as well. If the DNA fragments have net charge, the interaction with the potassium atoms at the surface of the mica might emerge as orienting force. The lattice of the mica has 60degree symmetry if I remember well, so the orientation might follow this pattern. I have seen similar in the case of amiloid fibrils, with the difference that they were growing on the surface of the mica but followed the lattice orientation.
G
Good day! I wonder is it obligatory to use gas gun to dry sample, or it is better to dry sample in dessicator? Previously I've used pretty the same methodology of sample preparation in my case. However, I had long chain fragments, a little bit different material, neutralized surface charges of mica, spin-coated/dropped material and left it dry in dessicator. And I have not mentioned any kind of preferable orientation of my material. Thus, maybe you should consider such a way.
If you have found current answer as useful, please, do not forget to reccommend it. That will help other researches to find the best answer, according to their purposes. Best of luck in your research!
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