Do letters of recommendation need to come from professors in your discipline?

[normalstudent]

Greetings,

 

First, I apologize if this question has been asked before but as  I did not find anything when I searched the forum I am posting this.

 

I'm a molecular biology major who is applying to similar PhD programs for next fall. I already have my P.I for the lab I do research in as one of my recommenders. But, for my other two letters I was wondering if it would be an issue if they both came from chemistry professors? Or should I focus on getting mainly biology professors? 

 

The reason I have these two chemistry professors in mind is because one of them was my organic professor( who has written two scholarship letters in the past as I did extremely well in his classes) and the other is a professor I have not had a class with but is the director/mentor of a scholarship program I have been involved in for the past year.

 

Does anyone with more experience feel that this could possibly pose a problem in anyway, or am I needlessly worrying?

 

Thanks

[Lisa44201]

You're needlessly worrying It's not a problem to get a letter from outside the department; as long as you've got at least one from bio, I think the other two can speak to different aspects of you as an applicant.