Choosing a lab rotation
More advice on this topic is woven into Navigating the Thesis Years - Directors Advice
Choosing a thesis lab is a huge decision. Make sure you research your options thoroughly and use all available resources when you are going through the process. In no particular order, these resources include your graduate group's lab rotation manual and website, the faculty themselves, Medline, your graduate group chair and coordinator, your MD-PhD faculty advisor, Maggie, and your fellow students (PhD and MD-PhD). Each fall the program puts together a panel of students to discuss this issue. First, second and third year students are very strongly encouraged to attend!
It is very important to keep in mind that finding science you really love is only one small part of the puzzle. Of course you want to find a lab that's doing fascinating science, and doing it successfully. But perhaps even more important is finding a mentor with whom you have a good fit. Part of this is learning everything you can about the mentor's style. There will be different advantages and disadvantages to every lab. A lot depends on your own personality and preferences. There are many continuums to consider, such as: huge lab vs. teeny lab, Assistant Professor vs. senior scientist, micro-management vs. laissez-faire leadership, being the only student vs. being one of a flock, etc. It's a lot to think about. Talk to everyone you can about the pros and cons of various aspects of mentors/labs that you are considering. Be especially sure to talk to students who have rotated through the lab before, if there are any. (Maggie can let you know which MD-PhD students have rotated through any given lab, and can also give you names of other students who have had that person on their thesis committee). Listen carefully to what they say - your peers are a great resource. Consider what they say about the mentor and also about what they were looking for in a lab. It may be that the very things that made a particular lab the wrong environment for them are the things that make it a great choice for you. Regardless of whether your preferences are similar or radically different, fellow students' opinions will help you gain insight. You should also talk extensively with the faculty member himself/herself about their style and expectations. Don't be afraid to ask direct questions.
First and second year students who have identified several labs of interest sometimes ask if they should save the one they think they'll like best for last. Their thought, reasonably enough, is that this would provide nice continuity from rotation into thesis work. DON'T DO THIS! It's virtually impossible to know if you'll be happy with a particular mentor until you've spent some real time in the lab. If you leave it for last and are unpleasantly surprised, you could end up in a tough spot. Instead, rotate through your first choice first, if space is available. If it feels like a perfect fit, it will give you great freedom for the next rotation or two- whether you choose a lab doing complementary research which will help you with your thesis, or choose a lab in a completely different area just to play with something new. But if that first choice turns out not to be the right fit, you'll still have time to find the right niche.
Remember that your Graduate Group and Skip will need to approve your choice of thesis lab and lab rotations.