apt

I am working on a research project under the guidance of a postdoc researcher at a professor's lab. I don't have much interaction with the professor, just with the postdoc. I am planning to apply for grad school and was wondering if it is acceptable to get a letter of recommendation from the postdoc instead of the professor as he is the one who knows me better. Will it harm my chances? Am I better off asking the professor in the hope that he'll talk to the postdoc about me?

@juilletmercredi: Both my master's GPAs are terrible in any sense of the word from a US perspective - they are around 2.7. But European universities (at least ones in the countries I went to) are very strict in their master's grading. On the ECTS (European Credit Transfer System) scale, my GPAs are categorized as "good". I mean, people who get a GPA like 3.3 are considered out of this world. Besides, I had some other issues - in case of my first masters, a lot of courses were taught in a foreign language which I had to learn simultaneously and in case of my second masters, I had some health issues. Would the US universities take that into consideration at all or will my application be subject to negative GPA filtering and rejected straight away? Also, what do you think of my GRE score (164 in both verbal and quantitative)? Thanks again.

Hi, I am an international student aspiring to get into a top 50 Biomedical Engineering PhD Program in the US. Here's my situation: - I have a bachelor's in physics with a decent GPA (my university did not give GPAs but my overall grade is equivalent of 3.7-3.8/4.0) from one of the best schools in my country (I'm from an Asian country, by the way) - I have a master's in applied physics from a European university which is among the best in its country but my grades are terrible. When I say terrible, I mean in terms of absolute numbers - I was still in the top half of my class. Anyway, the point is that it doesn't make good reading. - I have another master's, this time in biomedical engineering from a different European university which is also one of the best in its country. My grades in this case are better (in absolute terms) than for my previous master's but still not nearly as strong as my bachelor's grades. Also, since I was new to engineering, most of my classmates (who had engineering backgrounds) fared better than me. - I have no work experience and my research experience comes from my master's theses and a couple of projects during my bachelor's. I have no publications either. My GRE general scores are nothing special - 164/170 for both verbal and quantitative. The only plus point is that I was awarded fully funded scholarships for both my masters. Even though I have finally found the field I want to be in - biomedical engineering - my grades don't show a positive trend. And since I've very recently found my field of choice, I don't have much experience in it. So am I deluded to have a dream to get into a top 50 PhD program in the US? Should I even spend the money to apply this year? Would anyone have any suggestions as to what I can do to stand a chance? Thanks a ton in advance.