Does anyone else use DNA in your work?

Yes. I call it an "item of personal concern". Often time, just a strand of hair or clippings from fingernails is enough. I wouldn't use blood unless you're incredibly serious about binding yourself to whatever work it is. If you're doing Deadly Attraction and use some of your sexual fluids, it can definitely make the work potent/stronger.

Do you mean like dna fluids? like blood

It tailors the spell to you and makes it stronger

You might be about to find some relevant posts with a keyword search for the sample type you're using. I know folks are/do use it. I do not.

Following.