LORs from lab

[the defenestration]

I am applying to molecular bio programs in the fall, and I know it's really important for my recommenders to be able to comment on my performance in lab. My question is whether it's a good idea for all of my rec letters to be from people in my lab. I will of course get one from my PI, and I will probably get one from the neurosurgeon who helps with our in vivo studies. I may also ask one of our postdocs to write one. I feel they can all comment on different aspects of my work, so there shouldn't be too much repetition. On the other hand my research now is in biomaterials and I want to go into molecular bio, so I'm thinking I may want to get rec letters from some of my cell/molecular professors. Any opinions on the best course of action? I have two professors who could probably write me fairly strong letters, but they obviously don't know me as well as the people I've worked with in lab over the last year and a half.

One more question: all of my applications say to submit 3 rec letters. Is it common to be able to submit more rec letters than specified?

[rising_star]

Why not get someone that has interacted with you in a classroom as well?

[Eigen]

On the second part of your question:

None of the departments I applied to would allow more than the specified number of letters of rec- if you sent more than they asked for, they would either choose 3 at random, or use the first 3 submitted- which can sometimes work against you.

Contact the departments and ask, but you're probably better off choosing your "best" 3 for each program.