Career transition options?

I will be careful in my answer as the answer may be trekking on thin ice.

An MBA without any work experience is basically useless. A student goes to get his/her MBA usually after working for 3-7 years. What happens afterwards is that business school trains students in business acumen and while attending school, recruiters come and recruit the mid-level managers. Without any work experience, the recruiters will treat you essentially as someone who just graduated from college. And in that sense, the MBA becomes nothing but a degree you can put on your business card. In terms of online programs, it's not for everyone. The online programs target those who cannot make it on a full-time basis (perhaps because he/she makes minimum wage and has to take care of 3 kids, or military folks who don't want to be away from family). The online programs, as far as I can tell, do not guarantee you a job at all. In fact, most big corporate will most likely treat online programs as a joke. My strongest opinion would be this - please do not entertain the idea of getting an online MBA degree simply because you don't have a job right now or because you think this online MBA can get you a job afterwards. That's a fairly naive thought and I wouldn't want anyone to do it. There's really no such thing as "reputable" online MBAs, but if you still want to pursue it, University of Phoenix, Devry, and Kaplan University pop into my mind. Again, think twice before you commit yourself to doing this.

If I were you, find a job and do it for a few years. Science-degree graduates tend to think that in order to make it into business school, one has to be doing something "business-like", such as accounting or banking. That's simply not true. It's not about the type of job (or the title) that you do, but it's about the quality of the job. What impacts do you bring to the company as a whole. What leadership roles have you taken on both in and outside of your career. Those are way more important in an applicant's profile.

Just an fyi - I graduated with a biology degree as well. I found a job managing a laboratory space (plus an array of other actionable items); however, none of it has to do with "business". I was able to get into one of the best business schools in the nation to pursue my career goal. In retrospect, had I gone through the online MBA route (which I've thought about...), my opportunities would have diminished dramatically, if not disappeared.