Business casual would probably be best. However, I actually have gone to two interviews in scrubs (left PRN nob and went straight to interview) and I got both of the jobs!
I have always dressed business attire: tie, shirt, dress pants and shoes. MORE importantly I ALWAYS brought my portfolio with me. It contained my credentials, degrees, CEU, clearances, etc. The combination ALWAYS left the interviewer speechless and the job I went after was mine.
Scrubs! And a nice white labcoat.