Sci-Fi suggestions? How could telepathy work? If not DNA, what?

I'm developing a sci-fi story idea in my head and I would like scientifically plausible suggestions:





1. How could telepathy work? As in, what could be a proper medium? (Like voice is the medium for speech and gestures are the medium for sign languages.) A friend suggested nerve impulses, the same way the brain communicates with the body, but that can't work through the air, I don't think...? Plus, it's not telepathy in the sense many people know it, just sending thoughts; it's more sending words. Can electromagnetic waves work? Is there any other way? Ideally, I want something that could be recorded and transmitted electronically like images and voice can be.





2. I notice that most times that sci-fi discusses the genetic material of alien species, they use DNA, but that seems a bit unrealistic. If DNA isn't used for genetic material, is there anything else that could be used?








Thanks for any help.