My previous job was a temporary position for a company that was actually closing down. Since the work was getting slower and slower, I needed to get a new job and decided I wanted to move back to my college town. I took the first (and only) job offer I received, yet looking back I could have asked more in-depth questions about the job tasks in my interview. I love the company I work for and the employees, but it's not the career field I want to be in. My current occupation is in the food manufacturing industry in quality control and assurance but my deep interests lie more in DNA, stem cells, genetic testing, and more biologically/biochemical lab based environments. I find the work I currently do to be very boring and not at all intellectually challenging. My questions are 1) when is too early to quit without looking like I can't commit to a job and 2) what advice do you have that can help me get into a field I would truly enjoy?
1) when is too early to quit without looking like I can't commit to a job?
For your situation I would say 1 year would be a reasonable ballpark. I am assuming you are qualified for the types of positions you mention that you would be interested in. If so, then your current job does seem like a poor fit, in which case I see no reason to wait beyond 1 year. It shows you have some patience and can commit for a reasonable duration to a position in spite of it not being in your exact field.
For perspective, I realize this varies by industry but for instance, average tenure at Google is just over 1 year. It's a different age and a different yardstick of loyalty (which reflects its flip side of job stability). So I would not worry about leaving after putting in a year.
2) what advice do you have that can help me get into a field I would truly enjoy?
Align your qualifications to your interests. If this alignment already exists (college degree, past experience) then your chances of getting into a field you enjoy are as good as the next person's -- at least in terms of having the basics covered. If your education/experience does not represent a natural/typical pathway into a job you are interested in, it can be more of a challenge as the onus of responsibility for proving you (and not the next guy with more fitting credentials) deserve that dream job.
Also think about how to accentuate on you resume the skills and experiences that are valued in the types of positions you are interested in. In a competitive job market, presenting your qualifications in a way that is appropriate and impressive for each specific job to which you are applying is almost as important as having these qualifications.
Finally, do your research. Explore local and regional companies (or university research centers, or government agencies) that do the types of things you want to do. Perhaps it is a medical testing lab, or a large research lab at a univesity that often posts announcements for lab technicians.
Also think of "getting the foot in the door" at the right place. What this means is applying for a job that may be tangentially/indirectly related to the type of job you actually want to do. The goal is to get into the organization. Once you are in, be patient and wait for opportunities to come up that are more closely aligned to your interests, and pursue those. Hope this helps. Good luck!