100% agree. Just to add, as well as being difficult to perform, some experiments are highly sensitive to noise. In my experience, it's not uncommon in biology t

100% agree. Just to add, as well as being difficult to perform, some experiments are highly sensitive to noise. In my experience, it's not uncommon in biology to sometimes have difficulty replicating your own experiments. There are always more variables than can be controlled, e.g. environmental conditions, different batches of reagents, how you handle samples, how animals are housed, electrostatic effects from different glassware / plastics, small changes in the genetic background, etc.