How to follow up with potential PhD advisor met at conference? I recently attended a conference and met a professor who I would be interested in working with for my PhD. One of his students introduced us, and I mentioned some of my research interests, and he asked me about my GPA and GRE scores, and encouraged me to check the school website for application instructions and more information. He didn't seem very interested in talking more then, and I was not very familiar with his research, so I ended the conversation by asking if I could email him if I had any more questions. 
Now that I am back from the conference, I am wanting to follow up with him. I have read some of his papers now and was planning to ask a question about his research, but I was wondering if I should try to get a more committed response as to whether he would be interested in having me join his group? How should I bring this up?
Simply ask. Of course, your email should take in consideration PhD application instructions at his institution. If you can be admitted without an advisor, it changes the context. 

"Dear Dr. X,

It was a pleasure to meet you at conference Y and to discuss about Z. 

Since we met, I have read about your research area and [Insert question or comment].

Would it be possible to meet/skype to discuss the possibility of pursuing a PhD in your lab?"