Dressing appropriately for a job interview is a must. A reputable medical institution will surely not hire those who are wearing rubber shoes and have nose rings. You are in the interview place to get a job, not to party.
Dressing up conservatively is preferred by almost all companies. Most often men wear suits and women wear professional looking attire.
Women must see to it that they wear minimize jewelry and make-up. Avoid wearing strong fragrances because it might distract the interviewer. Once the interview starts, avoid looking at the floor and stop doing unnecessary gestures. You must also observe your posture – do not slouch!