If immigrants (relatives) in the United States want to do DNA testing, can they go back and get it? how much is it?

I recommend you to go to the United States for a test, which can be notarized in China.

Moreover, it is not cheap in China, 3000-6000, and the cost is different in different cities. And only large and medium-sized cities can do it. Although it is expensive in America, it is convenient and fast. It's not worth your time to travel back and forth.

In addition, it is hard to say whether the United States agrees or not. You know, the immigration service is for domestic enterprises, and they just want you to spend more in the United States.