What Kind of Doctor Do I Need? Slideshow Dental (Oral) Health Quiz Causes of a Heart Attack Slideshow In vitro: In glass, as in a test tube. An in vitro test is one that is done in glass or plastic vessels in the laboratory. In vitro is the opposite of in vivo. From Healthy Resources When Prostate Cancer SpreadsDo You Take Good Care of Your Eyes?Tips for a Clean Home & Healthy Cat Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? Therapy at Home?