Biochem is incredibly sensitive to seemingly minor changes in conditions or procedure. A former coworker of mine had to change careers after the procedure she had to follow to run the assays for her master's thesis gave her severe RSI. She couldn't alter the procedure for ergonomics, though, because even something like changing the angle that she held the pipettor at could throw off the results.

In biopharma work, it's not at all uncommon when trying to manufacture a biologic to find a process that works reliably in the lab but doesn't give the same results when scaled up to production-size bioreactors, such that there's often a whole stage of R&D devoted to taking a procedure from the lab and reproducing it on successively larger pieces of equipment, while working out all the tweaks and adjustments needed to make things work and optimize production.