How to ask for a LOR

[gocougs]

I'm applying for my M.S. (Molecular/Cell Biology) and need 2-3 letters of rec. The reason I am applying for an M.S. at all is my subpar undergrad academic resume: as a 4-year rower, I was more concerned with my sport than my grades, and my ADD (undiagnosed until last year, but now being treated) didn't help. I took a fifth year to both get a second B.S. (Biochemistry & Genetics/Cell Bio) and start on some novel undergrad research, which begins in my next (last) semester.

I've just gotten my grades for fall semester - all B+s and an A-. Can I ask the A- professor (or, rather, the organizing professor in a 3-lecturer course) for a recommendation? A poor performance on the first test and one missed assignment deadline (due to a total misunderstanding) were the only things between the A- and an A. I have a few other A-s, but no As in upper division major coursework up until this point. I also plan to ask the PI in my lab for a recommendation after a couple of months, but I won't have appreciable research work done for a while. Half of my applications are due the Feb 1, with the other half distributed all the way through the first of June.

My GREs were 169 V, 159 Q, 5.5 A, and I'm still waiting on my Biochem GRE score.