That&#x27;s simply not true. One of the most, if not the most, common ways to fail an experiment is through contamination and there are at least a dozen different types of bacteria in the average lab that are brutally efficient at outcompeting whatever is in your sample and probably thousands more that are problematic at best. Once your sample is contaminated it is useless because the number of variables out of your control grow several orders of magnitude in an already poorly bounded experiment.<p>Even if you have the best biosafety hood with proper airflow to pull things away from your samples, even the simple mistake of taking off your gloves in the hood or wafting your hands over petri dishes is enough for some skin cells carrying bacteria to wipe out an entire experiment.