i'm not the most informed person on this forum but here is my 2 cents.
If this is a job related lab work, I don't think it will be deleterious to your MD/SMP application. You might not able to get a good LoR from it, but you can very well spin the situation saying that you wanted to focus on other aspects toward your MD future.
Get out while you still can. And if asked about it (you probably won't unless MD/PhD), just say it wasn't a good fit and you didn't like the group. Or say a different/better opportunity came up, if it does.
Even the most qualified applicants/doctors/whoever have the potential for personality conflicts and things just not working out. No need to worry here! It's OK. Just focus on getting a new job- that's not something to be taken for granted these days. Breathe, you're going to be fine.