Volunteers are a very important part of scientific research, so I'm delighted that you're interested. Of course, each study is different and has specific requirements. You can take a look at the different studies we’re conducting at http://hnrc.tufts.edu/studies, or you can call the Volunteer Services Office at (800) 738-7555. They can tell you which Tufts research programs are currently recruiting participants, and they can explain the nature of the studies and their requirements.