How to follow up with a professor who had received my transcripts but did not reply? I inquired a professor at a reputable university regarding the per-requisite for his research group and if a certain knowledge is required, with a CV of mine. He asked for my transcripts. I mailed him my transcripts but have not got any reply yet. It has been 4 days. 

How should I approach the matter?
Keep waiting.  4 days is not very long.  If you have not heard anything in 3-4 weeks, send another email asking politely if he has had a chance to think about your request.